From ac22329c176a7847d6bcd313ada4e6e15f845ba4 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 5 Feb 2025 01:14:07 +0800
Subject: [PATCH 01/70] Initially copy and adapt some code to support `mill
 init` from an existing SBT project from its corresponding Gradle support

`SbtBuildGenMain.scala` and `BuildGenTests.scala` are not fully adapted yet, and the unadapted code is temporarily commented out.

An initial SBT plugin `ProjectTreePlugin` is added but not fully implemented yet. Only a task that writes some content to a file is added to test whether this approach works.

Exception in `./mill main.init.sbt.compile`:
```text
[1486] java.io.IOException: Scala signature package has wrong version
[1486]  expected: 5.0
[1486]  found: 5.2 in package.class
```

Corresponding code for Maven and Gradle is slightly improved BTW.
---
 build.mill                                    |   6 +-
 .../mill/main/gradle/GradleBuildGenMain.scala |   2 +-
 .../mill/main/maven/MavenBuildGenMain.scala   |   2 +-
 main/init/package.mill                        |  12 +-
 .../src/mill/main/sbt/ProjectTreePlugin.scala |  22 +
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 389 ++++++++++++++++++
 .../src/mill/main/sbt/BuildGenTests.scala     |  50 +++
 main/init/src/mill/init/InitSbtModule.scala   |  14 +
 main/src/mill/main/MainModule.scala           |   6 +
 9 files changed, 499 insertions(+), 4 deletions(-)
 create mode 100644 main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala
 create mode 100644 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
 create mode 100644 main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
 create mode 100644 main/init/src/mill/init/InitSbtModule.scala

diff --git a/build.mill b/build.mill
index edebba07bed..0c1386da6db 100644
--- a/build.mill
+++ b/build.mill
@@ -53,8 +53,11 @@ object Deps {
   // and then add to it `bridgeScalaVersions`
   val scalaVersion = "2.13.15"
   val scala2Version = "2.13.15"
+  // The Scala 2.12.x version
+  val scalaVersion212 = "2.12.20"
   // The Scala 2.12.x version to use for some workers
-  val workerScalaVersion212 = "2.12.20"
+  val workerScalaVersion212 = scalaVersion212
+  val sbtScalaVersion212 = scalaVersion212
 
   val testScala213Version = "2.13.15"
   // Scala Native 4.2 will not get releases for new Scala version
@@ -203,6 +206,7 @@ object Deps {
     ivy"org.apache.maven.resolver:maven-resolver-transport-wagon:$mavenResolverVersion"
   val coursierJvmIndexVersion = "0.0.4-84-f852c6"
   val gradleApi = ivy"dev.gradleplugins:gradle-api:8.11.1"
+  val sbt = ivy"org.scala-sbt:sbt:1.10.7"
 
   object RuntimeDeps {
     val dokkaVersion = "2.0.0"
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index 1906e5dc093..dfdd81cb72b 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -40,7 +40,7 @@ import scala.jdk.CollectionConverters.*
  */
 @mill.api.internal
 object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
-  type C = GradleBuildGenMain.Config
+  type C = Config
 
   def main(args: Array[String]): Unit = {
     val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index 9a77e9c8680..a8d9c0719a9 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -37,7 +37,7 @@ import scala.jdk.CollectionConverters.*
  */
 @mill.api.internal
 object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
-  type C = MavenBuildGenMain.Config
+  type C = Config
 
   def main(args: Array[String]): Unit = {
     val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
diff --git a/main/init/package.mill b/main/init/package.mill
index e99417eaee4..1fba01b92a7 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -1,7 +1,6 @@
 package build.main.init
 
 import mill._
-import scala.util.matching.Regex
 
 object `package` extends RootModule with build.MillPublishScalaModule {
 
@@ -86,4 +85,15 @@ object `package` extends RootModule with build.MillPublishScalaModule {
     )
     def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
   }
+
+  object sbt extends build.MillPublishScalaModule {
+    // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
+    def scalaVersion = build.Deps.sbtScalaVersion212
+
+    def moduleDeps = Seq(buildgen)
+
+    def ivyDeps = Agg(build.Deps.sbt, build.Deps.upickle)
+
+    def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
+  }
 }
diff --git a/main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala
new file mode 100644
index 00000000000..7e8558d54fc
--- /dev/null
+++ b/main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala
@@ -0,0 +1,22 @@
+package mill.main.sbt
+
+import sbt.Keys.target
+import sbt.{AutoPlugin, IO, Setting, taskKey}
+import sbt.io.syntax.*
+
+object ProjectTreePlugin extends AutoPlugin {
+  // override def requires = ???
+  object autoImport {
+    val millInitGenerateProjectTree = taskKey[File]("generate the project tree for `mill init`")
+  }
+  import autoImport.*
+
+  override lazy val globalSettings: Seq[Setting[_]] = Seq(
+    millInitGenerateProjectTree := {
+      // TODO
+      val outputFile = target.value / "mill-init-project-tree.json"
+      IO.write(outputFile, "test")
+      outputFile
+    }
+  )
+}
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
new file mode 100644
index 00000000000..b87ef0a4fb2
--- /dev/null
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -0,0 +1,389 @@
+package mill.main.sbt
+
+import mainargs.{ParserForClass, main}
+import mill.main.buildgen.*
+
+/**
+ * Converts an SBT build to Mill by generating Mill build file(s).
+ * The implementation uses the SBT
+ * [[https://www.scala-sbt.org/1.x/docs/Combined+Pages.html#addPluginSbtFile+command addPluginSbtFile command]]
+ * to add a plugin and a task to extract the settings for a project using a custom model.
+ *
+ * The generated output should be considered scaffolding and will likely require edits to complete conversion.
+ *
+ * ===Capabilities===
+ * The conversion
+ *  - handles deeply nested modules
+ *  - configures dependencies for configurations:
+ *    - Compile
+ *    - Runtime
+ *    - Test
+ *  - configures testing frameworks:
+ *    - JUnit 4
+ *    - JUnit 5
+ *    - TestNG
+ *    - ScalaTest
+ *    - Specs2
+ *    - ScalaCheck
+ * ===Limitations===
+ * The conversion does not support
+ *  - custom configurations
+ *  - custom tasks
+ *  - sources other than Scala on JVM and Java
+ */
+@mill.api.internal
+object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
+  type C = Config
+
+  def main(args: Array[String]): Unit = {
+    val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
+    run(cfg)
+  }
+
+  private def run(cfg: Config): Unit = {
+    val workspace = os.pwd
+
+    println("converting SBT build")
+
+
+    import scala.sys.process.*
+
+    // resolve the sbt executable
+    // https://raw.githubusercontent.com/paulp/sbt-extras/master/sbt
+    val sbtExecutable = if (os.exists(workspace / "sbt"))
+      "./sbt"
+    else if (os.exists(workspace / "sbtx"))
+      "./sbtx"
+    else if ("sbt --help".! == 0)
+      "sbt"
+    else
+      throw new RuntimeException(
+        "No sbt executable (`./sbt`, `./sbtx`, or system-wide `sbt`) found"
+      )
+
+    sbtExecutable.!
+
+    /*
+    val connector = GradleConnector.newConnector()
+
+    val args =
+      cfg.shared.jvmId.map { id =>
+        println(s"resolving Java home for jvmId $id")
+        val home = Jvm.resolveJavaHome(id).getOrThrow
+        s"-Dorg.gradle.java.home=$home"
+      } ++ Seq("--init-script", writeGradleInitScript.toString())
+
+    try {
+      println("connecting to Gradle daemon")
+      val connection = connector.forProjectDirectory(workspace.toIO).connect()
+      try {
+        val root = connection.model(classOf[ProjectTree])
+          .withArguments(args.asJava)
+          .get
+
+        val input = Tree.from(root) { tree =>
+          val project = tree.project()
+          val dirs = os.Path(project.directory()).subRelativeTo(workspace).segments
+          val children = tree.children().asScala.sortBy(_.project().name()).iterator
+          (Node(dirs, project), children)
+        }
+
+        convertWriteOut(cfg, cfg.shared, input)
+
+        println("converted Gradle build to Mill")
+      } finally connection.close()
+    } finally connector.disconnect()
+     */
+  }
+
+  /*
+  private def writeGradleInitScript: os.Path = {
+    val file = os.temp.dir() / "init.gradle"
+    val classpath =
+      os.Path(classOf[ProjectTreePlugin].getProtectionDomain.getCodeSource.getLocation.toURI)
+    val plugin = classOf[ProjectTreePlugin].getName
+    val contents =
+      s"""initscript {
+         |    dependencies {
+         |        classpath files(${escape(classpath.toString()) /* escape for Windows */})
+         |    }
+         |}
+         |
+         |allprojects {
+         |    apply plugin: $plugin
+         |}
+         |""".stripMargin
+    os.write(file, contents)
+    file
+  }
+   */
+
+  override def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[IrBuild]): Seq[String] =
+    ???
+
+  override def getBaseInfo(
+      input: Tree[Node[IrBuild]],
+      cfg: Config,
+      baseModule: String,
+      packagesSize: Int
+  ): IrBaseInfo = ???
+
+  override def getPackage(model: IrBuild): (String, String, String) = ???
+
+  override def getArtifactId(model: IrBuild): String = ???
+
+  override def extractIrBuild(
+      cfg: Config,
+      baseInfo: IrBaseInfo,
+      build: Node[IrBuild],
+      packages: Map[(String, String, String), String]
+  ): IrBuild = ???
+
+  /*
+  def getBaseInfo(
+      input: Tree[Node[ProjectModel]],
+      cfg: Config,
+      baseModule: String,
+      packagesSize: Int
+  ): IrBaseInfo = {
+    val project = {
+      val projects = input.nodes(Tree.Traversal.BreadthFirst).map(_.value).toSeq
+      cfg.baseProject
+        .flatMap(name => projects.collectFirst { case m if name == m.name => m })
+        .orElse(projects.collectFirst { case m if null != m.maven().pom() => m })
+        .orElse(projects.collectFirst { case m if !m.maven().repositories().isEmpty => m })
+        .getOrElse(input.node.value)
+    }
+    if (packagesSize > 1) {
+      println(s"settings from ${project.name()} will be shared in base module")
+    }
+    val supertypes =
+      Seq("MavenModule") ++
+        Option.when(null != project.maven().pom()) { "PublishModule" }
+
+    val javacOptions = getJavacOptions(project)
+    val repos = getRepositories(project)
+    val pomSettings = extractPomSettings(project)
+    val publishVersion = getPublishVersion(project)
+    val publishProperties = getPublishProperties(project, cfg.shared)
+
+    val typedef = IrTrait(
+      cfg.shared.jvmId,
+      baseModule,
+      supertypes,
+      javacOptions,
+      pomSettings,
+      publishVersion,
+      publishProperties,
+      repos
+    )
+
+    IrBaseInfo(javacOptions, repos, pomSettings == null, publishVersion, Seq.empty, typedef)
+  }
+
+  override def extractIrBuild(
+      cfg: Config,
+      baseInfo: IrBaseInfo,
+      build: Node[ProjectModel],
+      packages: Map[(String, String, String), String]
+  ): IrBuild = {
+    val project = build.value
+    val scopedDeps = extractScopedDeps(project, packages, cfg)
+    val version = getPublishVersion(project)
+    IrBuild(
+      scopedDeps = scopedDeps,
+      testModule = cfg.shared.testModule,
+      hasTest = os.exists(getMillSourcePath(project) / "src/test"),
+      dirs = build.dirs,
+      repositories = getRepositories(project).diff(baseInfo.repositories),
+      javacOptions = getJavacOptions(project).diff(baseInfo.javacOptions),
+      projectName = getArtifactId(project),
+      pomSettings = if (baseInfo.noPom) extractPomSettings(project) else null,
+      publishVersion = if (version == baseInfo.publishVersion) null else version,
+      packaging = getPomPackaging(project),
+      // not available
+      pomParentArtifact = null,
+      // skipped, requires relatively new API (JavaPluginExtension.getSourceSets)
+      resources = Nil,
+      testResources = Nil,
+      publishProperties = getPublishProperties(project, cfg.shared)
+    )
+  }
+
+  def getModuleSupertypes(cfg: Config): Seq[String] =
+    Seq(cfg.shared.baseModule.getOrElse("MavenModule"))
+
+  def getPackage(project: ProjectModel): (String, String, String) = {
+    (project.group(), project.name(), project.version())
+  }
+
+  def getArtifactId(model: ProjectModel): String = model.name()
+
+  def getMillSourcePath(model: ProjectModel): Path = os.Path(model.directory())
+
+  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] = {
+    Seq("RootModule") ++
+      Option.when(null != build.value.maven().pom() && baseInfo.noPom) { "PublishModule" } ++
+      Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
+        getModuleSupertypes(cfg)
+      }.toSeq.flatten
+  }
+
+  def groupArtifactVersion(dep: JavaModel.Dep): (String, String, String) =
+    (dep.group(), dep.name(), dep.version())
+
+  def getJavacOptions(project: ProjectModel): Seq[String] = {
+    val _java = project._java()
+    if (null == _java) Seq.empty
+    else _java.javacOptions().asScala.toSeq
+  }
+
+  def getRepositories(project: ProjectModel): Seq[String] =
+    project.maven().repositories().asScala.toSeq.sorted.map(uri =>
+      s"coursier.maven.MavenRepository(${escape(uri.toString)})"
+    )
+
+  def getPomPackaging(project: ProjectModel): String = {
+    val pom = project.maven().pom()
+    if (null == pom) null else pom.packaging()
+  }
+
+  def getPublishProperties(project: ProjectModel, cfg: BuildGenUtil.Config): Seq[(String, String)] =
+    if (cfg.publishProperties.value) {
+      val pom = project.maven().pom()
+      if (null == pom) Seq.empty
+      else pom.properties().iterator().asScala
+        .map(prop => (prop.key(), prop.value()))
+        .toSeq
+    } else Seq.empty
+
+  def getPublishVersion(project: ProjectModel): String =
+    project.version() match {
+      case "" | "unspecified" => null
+      case version => version
+    }
+
+  def interpIvy(dep: JavaModel.Dep): String = {
+    BuildGenUtil.renderIvyString(dep.group(), dep.name(), dep.version())
+  }
+
+  def extractPomSettings(project: ProjectModel): IrPom = {
+    val pom = project.maven.pom()
+    if (null == pom) null
+    else {
+      IrPom(
+        pom.description(),
+        project.group(), // Mill uses group for POM org
+        pom.url(),
+        licenses = pom.licenses().asScala
+          .map(lic => IrLicense(lic.name(), lic.name(), lic.url()))
+          .toSeq,
+        versionControl = Option(pom.scm()).fold(IrVersionControl(null, null, null, null))(scm =>
+          IrVersionControl(scm.url(), scm.connection(), scm.devConnection(), scm.tag())
+        ),
+        developers = pom.devs().asScala
+          .map(dev => IrDeveloper(dev.id(), dev.name(), dev.url(), dev.org(), dev.orgUrl()))
+          .toSeq
+      )
+    }
+  }
+
+  def extractScopedDeps(
+      project: ProjectModel,
+      packages: PartialFunction[(String, String, String), String],
+      cfg: Config
+  ): IrScopedDeps = {
+    var sd = IrScopedDeps()
+    val hasTest = os.exists(os.Path(project.directory()) / "src/test")
+    val _java = project._java()
+    if (null != _java) {
+      val ivyDep: JavaModel.Dep => String =
+        cfg.shared.depsObject.fold(interpIvy(_)) { objName => dep =>
+          val depName = s"`${dep.group()}:${dep.name()}`"
+          sd = sd.copy(namedIvyDeps = sd.namedIvyDeps :+ (depName, interpIvy(dep)))
+          s"$objName.$depName"
+        }
+
+      def appendIvyDepPackage(
+          deps: IterableOnce[JavaModel.Dep],
+          onPackage: String => IrScopedDeps,
+          onIvy: (String, (String, String, String)) => IrScopedDeps
+      ): Unit = {
+        for (dep <- deps.iterator) {
+          val id = groupArtifactVersion(dep)
+          if (packages.isDefinedAt(id)) sd = onPackage(packages(id))
+          else {
+            val ivy = ivyDep(dep)
+            sd = onIvy(ivy, id)
+          }
+        }
+      }
+      _java.configs().forEach { config =>
+        import JavaPlugin.*
+
+        val conf = config.name()
+        conf match {
+          case IMPLEMENTATION_CONFIGURATION_NAME | API_CONFIGURATION_NAME =>
+            appendIvyDepPackage(
+              config.deps.asScala,
+              onPackage = v => sd.copy(mainModuleDeps = sd.mainModuleDeps + v),
+              onIvy = (v, id) =>
+                if (isBom(id)) sd.copy(mainBomIvyDeps = sd.mainBomIvyDeps + v)
+                else sd.copy(mainIvyDeps = sd.mainIvyDeps + v)
+            )
+
+          case COMPILE_ONLY_CONFIGURATION_NAME | COMPILE_ONLY_API_CONFIGURATION_NAME =>
+
+            appendIvyDepPackage(
+              config.deps.asScala,
+              onPackage = v => sd.copy(mainCompileModuleDeps = sd.mainCompileModuleDeps + v),
+              onIvy = (v, id) => sd.copy(mainCompileIvyDeps = sd.mainCompileIvyDeps + v)
+            )
+
+          case RUNTIME_ONLY_CONFIGURATION_NAME =>
+            appendIvyDepPackage(
+              config.deps.asScala,
+              onPackage = v => sd.copy(mainRunModuleDeps = sd.mainRunModuleDeps + v),
+              onIvy = (v, id) => sd.copy(mainRunIvyDeps = sd.mainRunIvyDeps + v)
+            )
+
+          case TEST_IMPLEMENTATION_CONFIGURATION_NAME =>
+
+            appendIvyDepPackage(
+              config.deps.asScala,
+              onPackage = v => sd.copy(testModuleDeps = sd.testModuleDeps + v),
+              onIvy = (v, id) =>
+                if (isBom(id)) sd.copy(testBomIvyDeps = sd.testBomIvyDeps + v)
+                else sd.copy(testIvyDeps = sd.testIvyDeps + v)
+            )
+            config.deps.forEach { dep =>
+              if (hasTest && sd.testModule.isEmpty) {
+                sd = sd.copy(testModule = testModulesByGroup.get(dep.group()))
+              }
+            }
+
+          case TEST_COMPILE_ONLY_CONFIGURATION_NAME =>
+            appendIvyDepPackage(
+              config.deps.asScala,
+              onPackage = v => sd.copy(testCompileModuleDeps = sd.testCompileModuleDeps + v),
+              onIvy = (v, id) => sd.copy(testCompileIvyDeps = sd.testCompileIvyDeps + v)
+            )
+
+          case name =>
+            config.deps.forEach { dep =>
+              val id = groupArtifactVersion(dep)
+              println(s"ignoring $name dependency $id")
+            }
+        }
+      }
+    }
+    sd
+  }
+   */
+
+  @main
+  @mill.api.internal
+  case class Config(
+      shared: BuildGenUtil.Config
+  )
+}
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
new file mode 100644
index 00000000000..45762ac9e1b
--- /dev/null
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -0,0 +1,50 @@
+package mill.main.sbt
+
+import mill.main.buildgen.BuildGenChecker
+import utest.*
+
+object BuildGenTests extends TestSuite {
+
+  def tests: Tests = Tests {
+    val checker = BuildGenChecker()
+
+    /*
+    test("library") {
+      val sourceRoot = os.sub / "library"
+      val expectedRoot = os.sub / "expected/library"
+      assert(
+        checker.check(GradleBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
+      )
+    }
+
+    test("application-library") {
+      val sourceRoot = os.sub / "application-library"
+      val expectedRoot = os.sub / "expected/application-library"
+      assert(
+        checker.check(GradleBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
+      )
+    }
+
+    test("config") {
+      val sourceRoot = os.sub / "application-library"
+      val expectedRoot = os.sub / "expected/config"
+      val args = Array(
+        "--base-module",
+        "BaseModule",
+        "--base-project",
+        "utilities",
+        "--jvm-id",
+        "11",
+        "--test-module",
+        "tests",
+        "--deps-object",
+        "Deps",
+        "--merge"
+      )
+      assert(
+        checker.check(GradleBuildGenMain.main(args), sourceRoot, expectedRoot)
+      )
+    }
+     */
+  }
+}
diff --git a/main/init/src/mill/init/InitSbtModule.scala b/main/init/src/mill/init/InitSbtModule.scala
new file mode 100644
index 00000000000..4cf6dbd064a
--- /dev/null
+++ b/main/init/src/mill/init/InitSbtModule.scala
@@ -0,0 +1,14 @@
+package mill.init
+
+import mill.T
+import mill.api.{Loose, PathRef}
+import mill.define.{Discover, ExternalModule}
+
+@mill.api.experimental
+object InitSbtModule extends ExternalModule with BuildGenModule {
+  lazy val millDiscover: Discover = Discover[this.type]
+
+  def buildGenClasspath: T[Loose.Agg[PathRef]] = BuildGenModule.millModule("mill-main-init-sbt")
+
+  def buildGenMainClass: T[String] = "mill.main.sbt.SbtBuildGenMain"
+}
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index 61fbc18099c..6f1354fdba1 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -585,6 +585,12 @@ trait MainModule extends BaseModule0 {
             Seq("mill.init.InitGradleModule/init") ++ args,
             SelectMode.Separated
           )
+        else if (os.exists(os.pwd / "build.sbt"))
+          RunScript.evaluateTasksNamed(
+            evaluator,
+            Seq("mill.init.InitSbtModule/init") ++ args,
+            SelectMode.Separated
+          )
         else if (args.headOption.exists(_.toLowerCase.endsWith(".g8")))
           RunScript.evaluateTasksNamed(
             evaluator,

From d2ad6889a2a92d53db547bd5e2e3b19cb6dea5f9 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 5 Feb 2025 12:15:15 +0800
Subject: [PATCH 02/70] Add a cross module for the models and split the code
 because Mill uses Scala 2.13 while SBT uses Scala 2.12

`./mill main.init.sbt.test` passes now.
---
 build.mill                                    | 11 +++++-----
 main/init/package.mill                        | 21 ++++++++++++++-----
 .../sbt/models/src/mill/main/sbt/Models.scala |  3 +++
 .../src/mill/main/sbt/ProjectTreePlugin.scala |  1 +
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  2 ++
 5 files changed, 28 insertions(+), 10 deletions(-)
 create mode 100644 main/init/sbt/models/src/mill/main/sbt/Models.scala
 rename main/init/sbt/{ => sbt-mill-init-generate-project-tree}/src/mill/main/sbt/ProjectTreePlugin.scala (96%)

diff --git a/build.mill b/build.mill
index 0c1386da6db..8bfb7a7a934 100644
--- a/build.mill
+++ b/build.mill
@@ -181,7 +181,8 @@ object Deps {
   val sourcecode = ivy"com.lihaoyi::sourcecode:0.4.2"
   val upickle = ivy"com.lihaoyi::upickle:3.3.1"
   val windowsAnsi = ivy"io.github.alexarchambault.windows-ansi:windows-ansi:0.0.6"
-  val zinc = ivy"org.scala-sbt::zinc:1.10.7"
+  val sbtVersion = "1.10.7"
+  val zinc = ivy"org.scala-sbt::zinc:$sbtVersion"
   // keep in sync with doc/antora/antory.yml
   val bsp4j = ivy"ch.epfl.scala:bsp4j:2.2.0-M2"
   val fansi = ivy"com.lihaoyi::fansi:0.5.0"
@@ -206,7 +207,7 @@ object Deps {
     ivy"org.apache.maven.resolver:maven-resolver-transport-wagon:$mavenResolverVersion"
   val coursierJvmIndexVersion = "0.0.4-84-f852c6"
   val gradleApi = ivy"dev.gradleplugins:gradle-api:8.11.1"
-  val sbt = ivy"org.scala-sbt:sbt:1.10.7"
+  val sbt = ivy"org.scala-sbt:sbt:$sbtVersion"
 
   object RuntimeDeps {
     val dokkaVersion = "2.0.0"
@@ -641,8 +642,8 @@ trait BridgeModule extends MillPublishJavaModule with CrossScalaModule {
   def pomSettings = commonPomSettings(artifactName())
   def crossFullScalaVersion = true
   def ivyDeps = Agg(
-    ivy"org.scala-sbt:compiler-interface:${Deps.zinc.version}",
-    ivy"org.scala-sbt:util-interface:${Deps.zinc.version}",
+    ivy"org.scala-sbt:compiler-interface:${Deps.sbtVersion}",
+    ivy"org.scala-sbt:util-interface:${Deps.sbtVersion}",
     ivy"org.scala-lang:scala-compiler:${crossScalaVersion}"
   )
 
@@ -652,7 +653,7 @@ trait BridgeModule extends MillPublishJavaModule with CrossScalaModule {
   }
 
   def compilerBridgeIvyDeps: T[Agg[Dep]] = Agg(
-    ivy"org.scala-sbt::compiler-bridge:${Deps.zinc.version}".exclude("*" -> "*")
+    ivy"org.scala-sbt::compiler-bridge:${Deps.sbtVersion}".exclude("*" -> "*")
   )
 
   def compilerBridgeSourceJars: T[Agg[PathRef]] = Task {
diff --git a/main/init/package.mill b/main/init/package.mill
index 1fba01b92a7..a75863484fd 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -1,6 +1,7 @@
 package build.main.init
 
 import mill._
+import mill.scalalib.CrossScalaModule
 
 object `package` extends RootModule with build.MillPublishScalaModule {
 
@@ -87,13 +88,23 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   }
 
   object sbt extends build.MillPublishScalaModule {
-    // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
-    def scalaVersion = build.Deps.sbtScalaVersion212
+    def moduleDeps = Seq(buildgen, models(build.Deps.scalaVersion))
 
-    def moduleDeps = Seq(buildgen)
+    def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
 
-    def ivyDeps = Agg(build.Deps.sbt, build.Deps.upickle)
+    // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
+    object models
+        extends Cross[ModelsModule](build.Deps.sbtScalaVersion212, build.Deps.scalaVersion)
+    trait ModelsModule extends build.MillPublishJavaModule with CrossScalaModule {
+      def ivyDeps = Agg(build.Deps.upickle)
+    }
 
-    def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
+    // no need to publish this
+    object `sbt-mill-init-generate-project-tree` extends build.MillScalaModule {
+      private val scalaVersionString = build.Deps.sbtScalaVersion212
+      def scalaVersion = scalaVersionString
+      def moduleDeps = Seq(models(scalaVersionString))
+      def ivyDeps = Agg(build.Deps.sbt) // TODO consider `compileIvyDeps`
+    }
   }
 }
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
new file mode 100644
index 00000000000..b50e0ae3473
--- /dev/null
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -0,0 +1,3 @@
+package mill.main.sbt
+
+case class ProjectTree()
diff --git a/main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
similarity index 96%
rename from main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala
rename to main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
index 7e8558d54fc..ab4272e60e6 100644
--- a/main/init/sbt/src/mill/main/sbt/ProjectTreePlugin.scala
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
@@ -13,6 +13,7 @@ object ProjectTreePlugin extends AutoPlugin {
 
   override lazy val globalSettings: Seq[Setting[_]] = Seq(
     millInitGenerateProjectTree := {
+      ProjectTree()
       // TODO
       val outputFile = target.value / "mill-init-project-tree.json"
       IO.write(outputFile, "test")
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index b87ef0a4fb2..c7252d3ab7a 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -63,6 +63,8 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
 
     sbtExecutable.!
 
+    ProjectTree()
+
     /*
     val connector = GradleConnector.newConnector()
 

From 39f928e34beef224d551ff9557ec9ee0d3f81816 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 6 Feb 2025 12:47:51 +0800
Subject: [PATCH 03/70] Initially implement assembling and adding the
 `sbt-mill-init-generate-project-tree` plugin to an SBT build and writing and
 reading an empty `ProjectTree` model

`./mill main.init.sbt.test` and `./mill main.init.sbt.sbt-mill-init-generate-project-tree.compile` run successfully. Other than these 2, the changes are not fully tested yet.
---
 main/init/package.mill                        | 13 ++++++--
 .../sbt/models/src/mill/main/sbt/Models.scala |  5 +++
 .../src/mill/main/sbt/ProjectTreePlugin.scala | 10 +++---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 32 ++++++++-----------
 4 files changed, 35 insertions(+), 25 deletions(-)

diff --git a/main/init/package.mill b/main/init/package.mill
index a75863484fd..ec9c07fe405 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -1,7 +1,7 @@
 package build.main.init
 
 import mill._
-import mill.scalalib.CrossScalaModule
+import mill.scalalib.{CrossScalaModule, ScalaModule}
 
 object `package` extends RootModule with build.MillPublishScalaModule {
 
@@ -90,6 +90,14 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   object sbt extends build.MillPublishScalaModule {
     def moduleDeps = Seq(buildgen, models(build.Deps.scalaVersion))
 
+    // generateSbtPlugin
+    def sbtPluginResources = Task {
+      val assemblyPathRef = `sbt-mill-init-generate-project-tree`.assembly()
+      os.copy(assemblyPathRef.path, Task.dest / "sbt-mill-init-generate-project-tree.jar")
+      PathRef(Task.dest)
+    }
+    def resources: T[Seq[PathRef]] =
+      Task.Sources(super.resources() ++ Seq(sbtPluginResources()))
     def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
 
     // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
@@ -100,7 +108,8 @@ object `package` extends RootModule with build.MillPublishScalaModule {
     }
 
     // no need to publish this
-    object `sbt-mill-init-generate-project-tree` extends build.MillScalaModule {
+    // `test` fails with `build.MillScalaModule`, and since it's an SBT plugin project it's most likely not needed.
+    object `sbt-mill-init-generate-project-tree` extends ScalaModule {
       private val scalaVersionString = build.Deps.sbtScalaVersion212
       def scalaVersion = scalaVersionString
       def moduleDeps = Seq(models(scalaVersionString))
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index b50e0ae3473..983aa85b46b 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -1,3 +1,8 @@
 package mill.main.sbt
 
+import upickle.default.{ReadWriter => RW, macroRW}
+
 case class ProjectTree()
+object ProjectTree {
+  implicit val rw: RW[ProjectTree] = macroRW
+}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
index ab4272e60e6..93862f7dede 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
@@ -1,22 +1,24 @@
 package mill.main.sbt
 
 import sbt.Keys.target
+import sbt.io.syntax._
 import sbt.{AutoPlugin, IO, Setting, taskKey}
-import sbt.io.syntax.*
+import upickle.default._
 
 object ProjectTreePlugin extends AutoPlugin {
   // override def requires = ???
   object autoImport {
     val millInitGenerateProjectTree = taskKey[File]("generate the project tree for `mill init`")
   }
-  import autoImport.*
+  import autoImport._
 
   override lazy val globalSettings: Seq[Setting[_]] = Seq(
     millInitGenerateProjectTree := {
-      ProjectTree()
       // TODO
+      val projectTree = ProjectTree()
+
       val outputFile = target.value / "mill-init-project-tree.json"
-      IO.write(outputFile, "test")
+      IO.write(outputFile, write(projectTree))
       outputFile
     }
   )
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index c7252d3ab7a..6f64c0d3451 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -2,6 +2,7 @@ package mill.main.sbt
 
 import mainargs.{ParserForClass, main}
 import mill.main.buildgen.*
+import mill.main.buildgen.BuildGenUtil.escape
 
 /**
  * Converts an SBT build to Mill by generating Mill build file(s).
@@ -45,7 +46,6 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
 
     println("converting SBT build")
 
-
     import scala.sys.process.*
 
     // resolve the sbt executable
@@ -61,9 +61,11 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
         "No sbt executable (`./sbt`, `./sbtx`, or system-wide `sbt`) found"
       )
 
-    sbtExecutable.!
+    s"$sbtExecutable -addPluginSbtFile=${writeSbtFile().toString()} millInitGenerateProjectTree".!
 
-    ProjectTree()
+    import upickle.default.*
+    val projectTree = read[ProjectTree](os.read(workspace / "target" / "mill-init-project-tree.json"))
+    println("Project tree retrieved: " + projectTree)
 
     /*
     val connector = GradleConnector.newConnector()
@@ -98,27 +100,19 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
      */
   }
 
-  /*
-  private def writeGradleInitScript: os.Path = {
-    val file = os.temp.dir() / "init.gradle"
-    val classpath =
-      os.Path(classOf[ProjectTreePlugin].getProtectionDomain.getCodeSource.getLocation.toURI)
-    val plugin = classOf[ProjectTreePlugin].getName
+  private def writeSbtFile(): os.Path = {
+    val file = os.temp.dir() / "mill-init.sbt"
+    // TODO copy to a temp file if it doesn't work when packaged in a jar
+    val sbtPluginJarUrl =
+      getClass.getResource("/sbt-mill-init-generate-project-tree.jar").toExternalForm
     val contents =
-      s"""initscript {
-         |    dependencies {
-         |        classpath files(${escape(classpath.toString()) /* escape for Windows */})
-         |    }
-         |}
-         |
-         |allprojects {
-         |    apply plugin: $plugin
-         |}
+      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "" from ${escape(
+          sbtPluginJarUrl
+        )})
          |""".stripMargin
     os.write(file, contents)
     file
   }
-   */
 
   override def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[IrBuild]): Seq[String] =
     ???

From 3c9f155d1fd5e4146e22284d7104e02da83bbbcf Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 05:54:11 +0800
Subject: [PATCH 04/70] Add code to add the sbt plugin and run the
 `millInitGenerateProjectTree` sbt task in `SbtBuildGenMain`, create a
 "scala-seed-project" test project in test resources with `sbt new`, and
 update `ProjectTreePlugin`

`./mill main.init.sbt.test` fails.

In the sbt launched under the directory "main/init/sbt/test/resources/scala-seed-project" with `sbt -addPluginSbtFile=/.../mill-init.sbt` with the following content, the `tasks` sbt command output doesn't include an added `millInitGenerateProjectTree` task:

```sbt
addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "0.1.0-SNAPSHOT" from "file:/.../mill/out/main/init/sbt/sbtPluginResources.dest/sbt-mill-init-generate-project-tree.jar")
```

The following content of "mill-init.sbt" yields the following result:

```sbt
import mill.main.sbt.ProjectTreePlugin

addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "0.1.0-SNAPSHOT" from "file:/.../mill/out/main/init/sbt/sbtPluginResources.dest/sbt-mill-init-generate-project-tree.jar")

enablePlugins(ProjectTreePlugin)

lazy val root = (project in file("."))
  .enablePlugins(ProjectTreePlugin)

```

```text
/Users/shreckye/Projects/mill/mill-init.sbt:1: error: not found: object mill
import mill.main.sbt.ProjectTreePlugin
       ^
/Users/shreckye/Projects/mill/mill-init.sbt:8: error: not found: value ProjectTreePlugin
  .enablePlugins(ProjectTreePlugin)
                 ^
sbt.compiler.EvalException: Type error in expression
```

Reviewing the contents of https://repo1.maven.org/maven2/com/eed3si9n/sbt-assembly_2.12_1.0/2.3.1/sbt-assembly_2.12_1.0-2.3.1.jar, I see there is an "sbt/sbt.autoplugins" file which has the content:

```
sbtassembly.AssemblyPlugin

```

This probably means that such a file has to be included for an sbt plugin and a plain Mill module doesn't support this.
---
 .../src/mill/main/sbt/ProjectTreePlugin.scala |  5 ++--
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 23 +++++++++++++++----
 .../resources/scala-seed-project/.gitignore   |  2 ++
 .../resources/scala-seed-project/build.sbt    | 14 +++++++++++
 .../project/Dependencies.scala                |  5 ++++
 .../project/build.properties                  |  1 +
 .../src/main/scala/example/Hello.scala        |  9 ++++++++
 .../src/test/scala/example/HelloSpec.scala    |  7 ++++++
 .../src/mill/main/sbt/BuildGenTests.scala     | 10 ++++----
 9 files changed, 65 insertions(+), 11 deletions(-)
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/.gitignore
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/build.sbt
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/project/Dependencies.scala
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/project/build.properties
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/src/main/scala/example/Hello.scala
 create mode 100644 main/init/sbt/test/resources/scala-seed-project/src/test/scala/example/HelloSpec.scala

diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
index 93862f7dede..ddc2a1aceae 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
@@ -6,13 +6,14 @@ import sbt.{AutoPlugin, IO, Setting, taskKey}
 import upickle.default._
 
 object ProjectTreePlugin extends AutoPlugin {
-  // override def requires = ???
+  // override def requires = ??? // defaults to `JvmPlugin`
+  override def trigger = allRequirements
   object autoImport {
     val millInitGenerateProjectTree = taskKey[File]("generate the project tree for `mill init`")
   }
   import autoImport._
 
-  override lazy val globalSettings: Seq[Setting[_]] = Seq(
+  override lazy val buildSettings: Seq[Setting[_]] = Seq(
     millInitGenerateProjectTree := {
       // TODO
       val projectTree = ProjectTree()
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 6f64c0d3451..ae5a43e73b8 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -54,17 +54,32 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
       "./sbt"
     else if (os.exists(workspace / "sbtx"))
       "./sbtx"
-    else if ("sbt --help".! == 0)
+    else if (
+      // The return code is somehow 1 instead of 0.
+      Seq("sbt", "--help").!(ProcessLogger(_ => ())) == 1
+    )
       "sbt"
     else
       throw new RuntimeException(
         "No sbt executable (`./sbt`, `./sbtx`, or system-wide `sbt`) found"
       )
 
-    s"$sbtExecutable -addPluginSbtFile=${writeSbtFile().toString()} millInitGenerateProjectTree".!
+    println("Running sbt task to generate the project tree")
+
+    val exitCode = Process(
+      Seq(
+        sbtExecutable,
+        s"-addPluginSbtFile=${writeSbtFile().toString}",
+        "millInitGenerateProjectTree"
+      ),
+      workspace.toIO
+    ).!
+
+    println("Exit code from running the `millInitGenerateProjectTree` sbt task: " + exitCode)
 
     import upickle.default.*
-    val projectTree = read[ProjectTree](os.read(workspace / "target" / "mill-init-project-tree.json"))
+    val projectTree =
+      read[ProjectTree](os.read(workspace / "target" / "mill-init-project-tree.json"))
     println("Project tree retrieved: " + projectTree)
 
     /*
@@ -106,7 +121,7 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
     val sbtPluginJarUrl =
       getClass.getResource("/sbt-mill-init-generate-project-tree.jar").toExternalForm
     val contents =
-      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "" from ${escape(
+      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "0.1.0-SNAPSHOT" from ${escape(
           sbtPluginJarUrl
         )})
          |""".stripMargin
diff --git a/main/init/sbt/test/resources/scala-seed-project/.gitignore b/main/init/sbt/test/resources/scala-seed-project/.gitignore
new file mode 100644
index 00000000000..bddd1888af6
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/.gitignore
@@ -0,0 +1,2 @@
+/.bsp/
+target/
diff --git a/main/init/sbt/test/resources/scala-seed-project/build.sbt b/main/init/sbt/test/resources/scala-seed-project/build.sbt
new file mode 100644
index 00000000000..1dd2cd9d59c
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/build.sbt
@@ -0,0 +1,14 @@
+import Dependencies._
+
+ThisBuild / scalaVersion     := "2.13.12"
+ThisBuild / version          := "0.1.0-SNAPSHOT"
+ThisBuild / organization     := "com.example"
+ThisBuild / organizationName := "example"
+
+lazy val root = (project in file("."))
+  .settings(
+    name := "Scala Seed Project",
+    libraryDependencies += munit % Test
+  )
+
+// See https://www.scala-sbt.org/1.x/docs/Using-Sonatype.html for instructions on how to publish to Sonatype.
diff --git a/main/init/sbt/test/resources/scala-seed-project/project/Dependencies.scala b/main/init/sbt/test/resources/scala-seed-project/project/Dependencies.scala
new file mode 100644
index 00000000000..1edb07a723b
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/project/Dependencies.scala
@@ -0,0 +1,5 @@
+import sbt._
+
+object Dependencies {
+  lazy val munit = "org.scalameta" %% "munit" % "0.7.29"
+}
diff --git a/main/init/sbt/test/resources/scala-seed-project/project/build.properties b/main/init/sbt/test/resources/scala-seed-project/project/build.properties
new file mode 100644
index 00000000000..73df629ac1a
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/project/build.properties
@@ -0,0 +1 @@
+sbt.version=1.10.7
diff --git a/main/init/sbt/test/resources/scala-seed-project/src/main/scala/example/Hello.scala b/main/init/sbt/test/resources/scala-seed-project/src/main/scala/example/Hello.scala
new file mode 100644
index 00000000000..80ea40a9b31
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/src/main/scala/example/Hello.scala
@@ -0,0 +1,9 @@
+package example
+
+object Hello extends Greeting with App {
+  println(greeting)
+}
+
+trait Greeting {
+  lazy val greeting: String = "hello"
+}
diff --git a/main/init/sbt/test/resources/scala-seed-project/src/test/scala/example/HelloSpec.scala b/main/init/sbt/test/resources/scala-seed-project/src/test/scala/example/HelloSpec.scala
new file mode 100644
index 00000000000..d57b5ed4534
--- /dev/null
+++ b/main/init/sbt/test/resources/scala-seed-project/src/test/scala/example/HelloSpec.scala
@@ -0,0 +1,7 @@
+package example
+
+class HelloSpec extends munit.FunSuite {
+  test("say hello") {
+    assertEquals(Hello.greeting, "hello")
+  }
+}
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index 45762ac9e1b..ee5f9bcc7d0 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -8,15 +8,15 @@ object BuildGenTests extends TestSuite {
   def tests: Tests = Tests {
     val checker = BuildGenChecker()
 
-    /*
-    test("library") {
-      val sourceRoot = os.sub / "library"
-      val expectedRoot = os.sub / "expected/library"
+    test("scala-seed-project") {
+      val sourceRoot = os.sub / "scala-seed-project"
+      val expectedRoot = os.sub / "expected/scala-seed-project"
       assert(
-        checker.check(GradleBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
+        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
       )
     }
 
+    /*
     test("application-library") {
       val sourceRoot = os.sub / "application-library"
       val expectedRoot = os.sub / "expected/application-library"

From 923ddf4523f2ad515a71ef9fcadd4cd02e9f973f Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 05:57:55 +0800
Subject: [PATCH 05/70] Remove the files generated by sbt in
 "main/init/sbt/test/resources/scala-seed-project" and run `./mill
 main.init.sbt.test`

The exception:

```text
java.nio.file.NoSuchFileException: /Users/shreckye/Projects/mill/out/main/init/sbt/test/test.dest/sandbox/scala-seed-project/target/mill-init-project-tree.json
```

From 268eb6325daea7b91f5ed245b7982c1743e442a5 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 06:22:10 +0800
Subject: [PATCH 06/70] Replace "SBT"s with lowercase "sbt"

---
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index ae5a43e73b8..8f67a259004 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -5,8 +5,8 @@ import mill.main.buildgen.*
 import mill.main.buildgen.BuildGenUtil.escape
 
 /**
- * Converts an SBT build to Mill by generating Mill build file(s).
- * The implementation uses the SBT
+ * Converts an sbt build to Mill by generating Mill build file(s).
+ * The implementation uses the sbt
  * [[https://www.scala-sbt.org/1.x/docs/Combined+Pages.html#addPluginSbtFile+command addPluginSbtFile command]]
  * to add a plugin and a task to extract the settings for a project using a custom model.
  *
@@ -44,7 +44,7 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
   private def run(cfg: Config): Unit = {
     val workspace = os.pwd
 
-    println("converting SBT build")
+    println("converting sbt build")
 
     import scala.sys.process.*
 

From 86e180761e10f47908ca04af4e13dfd5293caa5d Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 06:59:27 +0800
Subject: [PATCH 07/70] Move the old "sbt-mill-init-generate-project-tree" Mill
 module and run `sbt new sbt/sbt-autoplugin.g8` in "main/init/sbt"

---
 .../src/mill/main/sbt/ProjectTreePlugin.scala |  0
 .../.gitignore                                | 11 ++++
 .../README.md                                 | 25 ++++++++
 .../build.sbt                                 | 58 +++++++++++++++++++
 .../project/build.properties                  |  1 +
 .../project/plugins.sbt                       |  4 ++
 .../MillinitgenerateprojecttreePlugin.scala   | 27 +++++++++
 .../simple/build.sbt                          |  2 +
 .../simple/project/plugins.sbt                |  7 +++
 .../simple/src/main/scala/Main.scala          | 19 ++++++
 .../simple/test                               |  1 +
 .../sbt/MillinitgenerateprojecttreeSpec.scala |  5 ++
 12 files changed, 160 insertions(+)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-generate-project-tree-mill}/src/mill/main/sbt/ProjectTreePlugin.scala (100%)
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/README.md
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
 create mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala

diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree-mill/src/mill/main/sbt/ProjectTreePlugin.scala
similarity index 100%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/src/mill/main/sbt/ProjectTreePlugin.scala
rename to main/init/sbt/sbt-mill-init-generate-project-tree-mill/src/mill/main/sbt/ProjectTreePlugin.scala
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore b/main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore
new file mode 100644
index 00000000000..f931b91f2ed
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore
@@ -0,0 +1,11 @@
+*.class
+*.log
+
+target
+project/project
+project/target
+.cache
+.classpath
+.project
+.settings
+bin
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/README.md b/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
new file mode 100644
index 00000000000..e3d7a84bafc
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
@@ -0,0 +1,25 @@
+# sbt-mill-init-generate-project-tree
+
+generate the project tree for `mill init`
+
+## Usage
+
+This plugin requires sbt 1.0.0+
+
+### Testing
+
+Run `test` for regular unit tests.
+
+Run `scripted` for [sbt script tests](http://www.scala-sbt.org/1.x/docs/Testing-sbt-plugins.html).
+
+### CI
+
+The generated project uses [sbt-github-actions](https://github.com/djspiewak/sbt-github-actions) as a plugin to generate workflows for GitHub actions. For full details of how to use it [read this](https://github.com/djspiewak/sbt-github-actions/blob/main/README.md)
+
+### Publishing
+
+1. publish your source to GitHub
+2. Follow the instructions in [sbt-ci-release](https://github.com/olafurpg/sbt-ci-release/blob/main/readme.md) to create a sonatype account and setup your keys
+3. `sbt ci-release`
+4. [Add your plugin to the community plugins list](https://github.com/sbt/website#attention-plugin-authors)
+5. [Claim your project an Scaladex](https://github.com/scalacenter/scaladex-contrib#claim-your-project)
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
new file mode 100644
index 00000000000..daf139cc2ac
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
@@ -0,0 +1,58 @@
+
+name := """sbt-mill-init-generate-project-tree"""
+organization := "com.lihaoyi"
+version := "0.1-SNAPSHOT"
+
+sbtPlugin := true
+
+// choose a test framework
+
+// utest
+//libraryDependencies += "com.lihaoyi" %% "utest" % "0.7.10" % "test"
+//testFrameworks += new TestFramework("utest.runner.Framework")
+
+// ScalaTest
+//libraryDependencies += "org.scalactic" %% "scalactic" % "3.2.9" % "test"
+//libraryDependencies += "org.scalatest" %% "scalatest" % "3.2.9" % "test"
+
+// Specs2
+//libraryDependencies ++= Seq("org.specs2" %% "specs2-core" % "4.12.8" % "test")
+//scalacOptions in Test ++= Seq("-Yrangepos")
+
+inThisBuild(List(
+  organization := "com.lihaoyi",
+  homepage := Some(url("https://github.com/com-lihaoyi/mill")),
+  licenses := List("Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-2.0")),
+  developers := List(
+    Developer(
+      "lihaoyi",
+      "Li Haoyi",
+      "haoyi.sg@gmail.com",
+      url("https://scala-lang.org")
+    )
+  )
+))
+
+initialCommands in console := """import mill.main.sbt._"""
+
+enablePlugins(ScriptedPlugin)
+// set up 'scripted; sbt plugin for testing sbt plugins
+scriptedLaunchOpts ++=
+  Seq("-Xmx1024M", "-Dplugin.version=" + version.value)
+
+ThisBuild / githubWorkflowTargetTags ++= Seq("v*")
+ThisBuild / githubWorkflowPublishTargetBranches :=
+  Seq(RefPredicate.StartsWith(Ref.Tag("v")))
+
+ThisBuild / githubWorkflowPublish := Seq(
+  WorkflowStep.Sbt(
+    List("ci-release"),
+    env = Map(
+      "PGP_PASSPHRASE" -> "${{ secrets.PGP_PASSPHRASE }}",
+      "PGP_SECRET" -> "${{ secrets.PGP_SECRET }}",
+      "SONATYPE_PASSWORD" -> "${{ secrets.SONATYPE_PASSWORD }}",
+      "SONATYPE_USERNAME" -> "${{ secrets.SONATYPE_USERNAME }}"
+    )
+  )
+)
+
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties b/main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties
new file mode 100644
index 00000000000..73df629ac1a
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties
@@ -0,0 +1 @@
+sbt.version=1.10.7
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
new file mode 100644
index 00000000000..65d78ae94a6
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
@@ -0,0 +1,4 @@
+libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value
+addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.7")
+addSbtPlugin("com.codecommit" % "sbt-github-actions" % "0.13.0")
+
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
new file mode 100644
index 00000000000..206c66d5f44
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
@@ -0,0 +1,27 @@
+package mill.main.sbt
+
+import sbt._
+import sbt.Keys._
+import sbt.plugins.JvmPlugin
+
+object MillinitgenerateprojecttreePlugin extends AutoPlugin {
+
+  override def trigger = allRequirements
+  override def requires = JvmPlugin
+
+  object autoImport {
+    val exampleSetting = settingKey[String]("A setting that is automatically imported to the build")
+    val exampleTask = taskKey[String]("A task that is automatically imported to the build")
+  }
+
+  import autoImport._
+
+  override lazy val projectSettings = Seq(
+    exampleSetting := "just an example",
+    exampleTask := "computed from example setting: " + exampleSetting.value
+  )
+
+  override lazy val buildSettings = Seq()
+
+  override lazy val globalSettings = Seq()
+}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
new file mode 100644
index 00000000000..bce0be88ace
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
@@ -0,0 +1,2 @@
+version := "0.1"
+scalaVersion := "2.12.1"
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
new file mode 100644
index 00000000000..1bf98d6cba8
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
@@ -0,0 +1,7 @@
+{
+  val pluginVersion = System.getProperty("plugin.version")
+  if(pluginVersion == null)
+    throw new RuntimeException("""|The system property 'plugin.version' is not defined.
+                                  |Specify this property using the scriptedLaunchOpts -D.""".stripMargin)
+  else addSbtPlugin("com.lihaoyi" % """sbt-mill-init-generate-project-tree""" % pluginVersion)
+}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
new file mode 100644
index 00000000000..363b8d4f10a
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
@@ -0,0 +1,19 @@
+package simple
+
+/**
+  * A simple class and objects to write tests against.
+  */
+class Main {
+  val default = "the function returned"
+  def method = default + " " + Main.function
+}
+
+object Main {
+
+  val constant = 1
+  def function = 2*constant
+
+  def main(args: Array[String]): Unit = {
+    println(new Main().default)
+  }
+}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
new file mode 100644
index 00000000000..f458fe34665
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
@@ -0,0 +1 @@
+> show exampleTask
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala
new file mode 100644
index 00000000000..c4d6adc1969
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala
@@ -0,0 +1,5 @@
+package mill.main.sbt
+
+class MillinitgenerateprojecttreeTest {
+  // write tests with your preferred framework
+}

From 9991d8a766c9b9de6bd2d294d2bae11cea514dec Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 07:22:31 +0800
Subject: [PATCH 08/70] =?UTF-8?q?Remove=20unneeded=20code=20in=20the=20gen?=
 =?UTF-8?q?erated=20sbt=20plugin=20project=20and=20add=20=C2=B5Test=20to?=
 =?UTF-8?q?=20the=20testing=20frameworks=20BTW=20in=20the=20Scaladoc=20of?=
 =?UTF-8?q?=20`SbtBuildGenMain`?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../build.sbt                                 | 52 +------------------
 .../project/plugins.sbt                       |  4 --
 .../simple/build.sbt                          |  2 -
 .../simple/project/plugins.sbt                |  7 ---
 .../simple/src/main/scala/Main.scala          | 19 -------
 .../simple/test                               |  1 -
 .../sbt/MillinitgenerateprojecttreeSpec.scala |  5 --
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  1 +
 8 files changed, 2 insertions(+), 89 deletions(-)
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala

diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
index daf139cc2ac..65d0e5fc85d 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
@@ -5,54 +5,4 @@ version := "0.1-SNAPSHOT"
 
 sbtPlugin := true
 
-// choose a test framework
-
-// utest
-//libraryDependencies += "com.lihaoyi" %% "utest" % "0.7.10" % "test"
-//testFrameworks += new TestFramework("utest.runner.Framework")
-
-// ScalaTest
-//libraryDependencies += "org.scalactic" %% "scalactic" % "3.2.9" % "test"
-//libraryDependencies += "org.scalatest" %% "scalatest" % "3.2.9" % "test"
-
-// Specs2
-//libraryDependencies ++= Seq("org.specs2" %% "specs2-core" % "4.12.8" % "test")
-//scalacOptions in Test ++= Seq("-Yrangepos")
-
-inThisBuild(List(
-  organization := "com.lihaoyi",
-  homepage := Some(url("https://github.com/com-lihaoyi/mill")),
-  licenses := List("Apache-2.0" -> url("http://www.apache.org/licenses/LICENSE-2.0")),
-  developers := List(
-    Developer(
-      "lihaoyi",
-      "Li Haoyi",
-      "haoyi.sg@gmail.com",
-      url("https://scala-lang.org")
-    )
-  )
-))
-
-initialCommands in console := """import mill.main.sbt._"""
-
-enablePlugins(ScriptedPlugin)
-// set up 'scripted; sbt plugin for testing sbt plugins
-scriptedLaunchOpts ++=
-  Seq("-Xmx1024M", "-Dplugin.version=" + version.value)
-
-ThisBuild / githubWorkflowTargetTags ++= Seq("v*")
-ThisBuild / githubWorkflowPublishTargetBranches :=
-  Seq(RefPredicate.StartsWith(Ref.Tag("v")))
-
-ThisBuild / githubWorkflowPublish := Seq(
-  WorkflowStep.Sbt(
-    List("ci-release"),
-    env = Map(
-      "PGP_PASSPHRASE" -> "${{ secrets.PGP_PASSPHRASE }}",
-      "PGP_SECRET" -> "${{ secrets.PGP_SECRET }}",
-      "SONATYPE_PASSWORD" -> "${{ secrets.SONATYPE_PASSWORD }}",
-      "SONATYPE_USERNAME" -> "${{ secrets.SONATYPE_USERNAME }}"
-    )
-  )
-)
-
+console / initialCommands := """import mill.main.sbt._"""
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
index 65d78ae94a6..e69de29bb2d 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
@@ -1,4 +0,0 @@
-libraryDependencies += "org.scala-sbt" %% "scripted-plugin" % sbtVersion.value
-addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.7")
-addSbtPlugin("com.codecommit" % "sbt-github-actions" % "0.13.0")
-
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
deleted file mode 100644
index bce0be88ace..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/build.sbt
+++ /dev/null
@@ -1,2 +0,0 @@
-version := "0.1"
-scalaVersion := "2.12.1"
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
deleted file mode 100644
index 1bf98d6cba8..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/project/plugins.sbt
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-  val pluginVersion = System.getProperty("plugin.version")
-  if(pluginVersion == null)
-    throw new RuntimeException("""|The system property 'plugin.version' is not defined.
-                                  |Specify this property using the scriptedLaunchOpts -D.""".stripMargin)
-  else addSbtPlugin("com.lihaoyi" % """sbt-mill-init-generate-project-tree""" % pluginVersion)
-}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
deleted file mode 100644
index 363b8d4f10a..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/src/main/scala/Main.scala
+++ /dev/null
@@ -1,19 +0,0 @@
-package simple
-
-/**
-  * A simple class and objects to write tests against.
-  */
-class Main {
-  val default = "the function returned"
-  def method = default + " " + Main.function
-}
-
-object Main {
-
-  val constant = 1
-  def function = 2*constant
-
-  def main(args: Array[String]): Unit = {
-    println(new Main().default)
-  }
-}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test b/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
deleted file mode 100644
index f458fe34665..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/sbt-test/sbt-mill-init-generate-project-tree/simple/test
+++ /dev/null
@@ -1 +0,0 @@
-> show exampleTask
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala
deleted file mode 100644
index c4d6adc1969..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/test/scala/mill/main/sbt/MillinitgenerateprojecttreeSpec.scala
+++ /dev/null
@@ -1,5 +0,0 @@
-package mill.main.sbt
-
-class MillinitgenerateprojecttreeTest {
-  // write tests with your preferred framework
-}
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 8f67a259004..04056e9e6c5 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -23,6 +23,7 @@ import mill.main.buildgen.BuildGenUtil.escape
  *    - JUnit 4
  *    - JUnit 5
  *    - TestNG
+ *    - µTest
  *    - ScalaTest
  *    - Specs2
  *    - ScalaCheck

From a253537f43c5defaf7d60f3851a2861a2af07a17 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Fri, 7 Feb 2025 11:45:56 +0800
Subject: [PATCH 09/70] Move `ProjectTreePlugin` into the sbt project and set
 up the build logic that jumps between Mill and sbt

The issues in commit 3c9f155d1fd5e4146e22284d7104e02da83bbbcf are resolved and `./mill main.init.sbt.test` now passes.
---
 main/init/package.mill                        | 39 ++++++++++++-------
 .../README.md                                 | 27 +++----------
 .../build.sbt                                 |  4 +-
 .../project/plugins.sbt                       |  1 +
 .../MillinitgenerateprojecttreePlugin.scala   | 27 -------------
 .../mill/main/sbt/ProjectTreePlugin.scala     | 13 ++++---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  2 +-
 7 files changed, 43 insertions(+), 70 deletions(-)
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
 rename main/init/sbt/{sbt-mill-init-generate-project-tree-mill/src => sbt-mill-init-generate-project-tree/src/main/scala}/mill/main/sbt/ProjectTreePlugin.scala (74%)

diff --git a/main/init/package.mill b/main/init/package.mill
index ec9c07fe405..91d51a866ea 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -1,7 +1,7 @@
 package build.main.init
 
 import mill._
-import mill.scalalib.{CrossScalaModule, ScalaModule}
+import mill.scalalib.CrossScalaModule
 
 object `package` extends RootModule with build.MillPublishScalaModule {
 
@@ -90,14 +90,32 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   object sbt extends build.MillPublishScalaModule {
     def moduleDeps = Seq(buildgen, models(build.Deps.scalaVersion))
 
-    // generateSbtPlugin
-    def sbtPluginResources = Task {
-      val assemblyPathRef = `sbt-mill-init-generate-project-tree`.assembly()
-      os.copy(assemblyPathRef.path, Task.dest / "sbt-mill-init-generate-project-tree.jar")
+    // generateSbtPluginJar
+    def sbtPluginJarResources = Task {
+      models(build.Deps.sbtScalaVersion212).publishLocal()()
+
+      import scala.sys.process._
+      val sbtProjectPath = millModuleBasePath.value / "sbt-mill-init-generate-project-tree"
+      val version = build.millVersion()
+      if (
+        Process(
+          // The version is passed to the sbt build so it correctly resolves the "models" dependency version and sets its own version.
+          s"""sbt 'set version := "$version"' assembly""",
+          sbtProjectPath.toIO
+        ).! != 0
+      )
+        throw new RuntimeException(
+          "fail to run `sbt assembly` in the \"sbt-mill-init-generate-project-tree\" sbt project."
+        )
+
+      os.copy(
+        sbtProjectPath / "target" / "scala-2.12" / "sbt-1.0" / s"sbt-mill-init-generate-project-tree-assembly-$version.jar",
+        Task.dest / "sbt-mill-init-generate-project-tree-assembly.jar"
+      )
       PathRef(Task.dest)
     }
     def resources: T[Seq[PathRef]] =
-      Task.Sources(super.resources() ++ Seq(sbtPluginResources()))
+      Task.Sources(super.resources() ++ Seq(sbtPluginJarResources()))
     def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib, buildgen.test)
 
     // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
@@ -106,14 +124,5 @@ object `package` extends RootModule with build.MillPublishScalaModule {
     trait ModelsModule extends build.MillPublishJavaModule with CrossScalaModule {
       def ivyDeps = Agg(build.Deps.upickle)
     }
-
-    // no need to publish this
-    // `test` fails with `build.MillScalaModule`, and since it's an SBT plugin project it's most likely not needed.
-    object `sbt-mill-init-generate-project-tree` extends ScalaModule {
-      private val scalaVersionString = build.Deps.sbtScalaVersion212
-      def scalaVersion = scalaVersionString
-      def moduleDeps = Seq(models(scalaVersionString))
-      def ivyDeps = Agg(build.Deps.sbt) // TODO consider `compileIvyDeps`
-    }
   }
 }
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/README.md b/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
index e3d7a84bafc..55e348119f8 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
@@ -1,25 +1,10 @@
 # sbt-mill-init-generate-project-tree
 
-generate the project tree for `mill init`
+An sbt plugin to generate the project tree for `mill init`
 
-## Usage
+## Working on this project
 
-This plugin requires sbt 1.0.0+
-
-### Testing
-
-Run `test` for regular unit tests.
-
-Run `scripted` for [sbt script tests](http://www.scala-sbt.org/1.x/docs/Testing-sbt-plugins.html).
-
-### CI
-
-The generated project uses [sbt-github-actions](https://github.com/djspiewak/sbt-github-actions) as a plugin to generate workflows for GitHub actions. For full details of how to use it [read this](https://github.com/djspiewak/sbt-github-actions/blob/main/README.md)
-
-### Publishing
-
-1. publish your source to GitHub
-2. Follow the instructions in [sbt-ci-release](https://github.com/olafurpg/sbt-ci-release/blob/main/readme.md) to create a sonatype account and setup your keys
-3. `sbt ci-release`
-4. [Add your plugin to the community plugins list](https://github.com/sbt/website#attention-plugin-authors)
-5. [Claim your project an Scaladex](https://github.com/scalacenter/scaladex-contrib#claim-your-project)
+Make sure you are on the SNAPSHOT version of Mill,
+and run `./mill "main.init.sbt.models[2.12.20].publishLocal"`,
+to publish the models to Ivy's local repository before working on this project.
+Then open this directory as a separate IntelliJ IDEA project as this is an sbt project.
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
index 65d0e5fc85d..9ee673f5ba5 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
@@ -1,8 +1,10 @@
 
 name := """sbt-mill-init-generate-project-tree"""
 organization := "com.lihaoyi"
-version := "0.1-SNAPSHOT"
+version := "SNAPSHOT"
 
 sbtPlugin := true
 
 console / initialCommands := """import mill.main.sbt._"""
+
+libraryDependencies += "com.lihaoyi" %% "mill-main-init-sbt-models" % version.value
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
index e69de29bb2d..f8ea5d0fbb0 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
@@ -0,0 +1 @@
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.3.1")
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
deleted file mode 100644
index 206c66d5f44..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/MillinitgenerateprojecttreePlugin.scala
+++ /dev/null
@@ -1,27 +0,0 @@
-package mill.main.sbt
-
-import sbt._
-import sbt.Keys._
-import sbt.plugins.JvmPlugin
-
-object MillinitgenerateprojecttreePlugin extends AutoPlugin {
-
-  override def trigger = allRequirements
-  override def requires = JvmPlugin
-
-  object autoImport {
-    val exampleSetting = settingKey[String]("A setting that is automatically imported to the build")
-    val exampleTask = taskKey[String]("A task that is automatically imported to the build")
-  }
-
-  import autoImport._
-
-  override lazy val projectSettings = Seq(
-    exampleSetting := "just an example",
-    exampleTask := "computed from example setting: " + exampleSetting.value
-  )
-
-  override lazy val buildSettings = Seq()
-
-  override lazy val globalSettings = Seq()
-}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree-mill/src/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
similarity index 74%
rename from main/init/sbt/sbt-mill-init-generate-project-tree-mill/src/mill/main/sbt/ProjectTreePlugin.scala
rename to main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
index ddc2a1aceae..3fe31be4d2e 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree-mill/src/mill/main/sbt/ProjectTreePlugin.scala
+++ b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
@@ -1,19 +1,22 @@
 package mill.main.sbt
 
 import sbt.Keys.target
-import sbt.io.syntax._
+import sbt.io.syntax.*
 import sbt.{AutoPlugin, IO, Setting, taskKey}
-import upickle.default._
+import upickle.default.*
 
 object ProjectTreePlugin extends AutoPlugin {
-  // override def requires = ??? // defaults to `JvmPlugin`
   override def trigger = allRequirements
+  // override def requires = ??? // defaults to `JvmPlugin`
+
   object autoImport {
     val millInitGenerateProjectTree = taskKey[File]("generate the project tree for `mill init`")
   }
-  import autoImport._
 
-  override lazy val buildSettings: Seq[Setting[_]] = Seq(
+  import autoImport.*
+
+  // `target.value` doesn't work in `globalSettings` and `buildSettings`
+  override lazy val projectSettings: Seq[Setting[_]] = Seq(
     millInitGenerateProjectTree := {
       // TODO
       val projectTree = ProjectTree()
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 04056e9e6c5..ff0ea7e3acd 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -120,7 +120,7 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
     val file = os.temp.dir() / "mill-init.sbt"
     // TODO copy to a temp file if it doesn't work when packaged in a jar
     val sbtPluginJarUrl =
-      getClass.getResource("/sbt-mill-init-generate-project-tree.jar").toExternalForm
+      getClass.getResource("/sbt-mill-init-generate-project-tree-assembly.jar").toExternalForm
     val contents =
       s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "0.1.0-SNAPSHOT" from ${escape(
           sbtPluginJarUrl

From 01bfcf5fbd26c15ce8b88483506f0dd43e4c0943 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sat, 15 Feb 2025 20:48:49 +0800
Subject: [PATCH 10/70] Initially complete implementing `SbtBuildGenMain` and
 the sbt plugin project "sbt-mill-init-export-build", and generate build files
 for "scala-seed-project" in the test resources

The generated "scala-seed-project" "build.mill" file is not completely correct yet.

Changes:

* All kinds of necessary model case classes are added in "Models.scala" in the "models" module.
* A `MillPublishCrossScalaModule` is extracted in the Mill build files.
* The sbt plugin project "sbt-mill-init-generate-project-tree" is renamed to "sbt-mill-init-export-build" as the plugin doesn't just export a tree of projects.
* An `sbtPluginProjectSource` `Source` task is added in the `sbt` module's Mill build configuration to react to changes in the sbt Plugin project.
* `BuildGenBase` is updated with a new type parameter `I` for `input`, as the `IrBaseInfo` is not retrieved from a module in sbt but from `ThisBuild`, and thus `BuildExport.defaultBuildInfo` needs to be passed.
  * A `BaseInfoFromSubproject` subtype trait is added.
  * A `BasicConfig` is extracted from `Config` for sbt.
* `MavenBuildGenMain` and `GradleBuildGenMain` are updated accordingly and slightly improved.
* Changes in `BuildGenUtil`:
  * `scalacOptions` is added similar to `javacOptions`.
  * More Scala test frameworks are added in `testModulesByGroup`.
---
 build.mill                                    |   4 +-
 .../src/mill/main/buildgen/BuildGenBase.scala |  25 +-
 .../src/mill/main/buildgen/BuildGenUtil.scala |  49 +-
 .../buildgen/src/mill/main/buildgen/ir.scala  |  13 +
 .../mill/main/gradle/GradleBuildGenMain.scala |  27 +-
 .../mill/main/maven/MavenBuildGenMain.scala   |  28 +-
 main/init/package.mill                        |  31 +-
 .../sbt/models/src/mill/main/sbt/Models.scala | 307 ++++++++++-
 .../.gitignore                                |   0
 .../README.md                                 |   2 +-
 .../build.sbt                                 |   3 +-
 .../project/build.properties                  |   0
 .../project/plugins.sbt                       |   0
 .../mill/main/sbt/ExportBuildPlugin.scala     | 247 +++++++++
 .../mill/main/sbt/ProjectTreePlugin.scala     |  29 --
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 487 +++++++++---------
 .../expected/scala-seed-project/build.mill    |  29 ++
 .../src/mill/main/sbt/BuildGenTests.scala     |   2 +-
 18 files changed, 953 insertions(+), 330 deletions(-)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-export-build}/.gitignore (100%)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-export-build}/README.md (84%)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-export-build}/build.sbt (80%)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-export-build}/project/build.properties (100%)
 rename main/init/sbt/{sbt-mill-init-generate-project-tree => sbt-mill-init-export-build}/project/plugins.sbt (100%)
 create mode 100644 main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
 delete mode 100644 main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
 create mode 100644 main/init/sbt/test/resources/expected/scala-seed-project/build.mill

diff --git a/build.mill b/build.mill
index 8bfb7a7a934..a16a98e60d7 100644
--- a/build.mill
+++ b/build.mill
@@ -634,8 +634,10 @@ trait MillStableScalaModule extends MillPublishScalaModule with Mima {
   def skipPreviousVersions: T[Seq[String]] = T(Seq.empty[String])
 }
 
+trait MillPublishCrossScalaModule extends MillPublishJavaModule with CrossScalaModule
+
 object bridge extends Cross[BridgeModule](compilerBridgeScalaVersions)
-trait BridgeModule extends MillPublishJavaModule with CrossScalaModule {
+trait BridgeModule extends MillPublishCrossScalaModule {
   def scalaVersion = crossScalaVersion
   def publishVersion = bridgeVersion
   def artifactName = "mill-scala-compiler-bridge"
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 73e846c04bf..261e5d58615 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -4,26 +4,29 @@ import mill.main.buildgen.BuildGenUtil.{buildPackages, compactBuildTree, writeBu
 
 import scala.collection.immutable.SortedMap
 
-trait BuildGenBase[M, D] {
+trait BuildGenBase[M, D, I] {
   type C
-  def convertWriteOut(cfg: C, shared: BuildGenUtil.Config, input: Tree[Node[M]]): Unit = {
+  def convertWriteOut(cfg: C, shared: BuildGenUtil.BasicConfig, input: I): Unit = {
     val output = convert(input, cfg, shared)
     writeBuildObject(if (shared.merge.value) compactBuildTree(output) else output)
   }
 
+  def getProjectTree(input: I): Tree[Node[M]]
+
   def convert(
-      input: Tree[Node[M]],
+      input: I,
       cfg: C,
-      shared: BuildGenUtil.Config
+      shared: BuildGenUtil.BasicConfig
   ): Tree[Node[BuildObject]] = {
-    // for resolving moduleDeps
+    val projectTree = getProjectTree(input)
 
-    val packages = buildPackages(input)(getPackage)
+    // for resolving moduleDeps
+    val packages = buildPackages(projectTree)(getPackage)
 
     val baseInfo =
       shared.baseModule.fold(IrBaseInfo()) { getBaseInfo(input, cfg, _, packages.size) }
 
-    input.map { build =>
+    projectTree.map { build =>
       val name = getArtifactId(build.value)
       println(s"converting module $name")
 
@@ -50,7 +53,7 @@ trait BuildGenBase[M, D] {
   def getSuperTypes(cfg: C, baseInfo: IrBaseInfo, build: Node[M]): Seq[String]
 
   def getBaseInfo(
-      input: Tree[Node[M]],
+      input: I,
       cfg: C,
       baseModule: String,
       packagesSize: Int
@@ -67,3 +70,9 @@ trait BuildGenBase[M, D] {
       packages: Map[(String, String, String), String]
   ): IrBuild
 }
+
+object BuildGenBase {
+  trait BaseInfoFromSubproject[M, D] extends BuildGenBase[M, D, Tree[Node[M]]] {
+    override def getProjectTree(input: Tree[Node[M]]): Tree[Node[M]] = input
+  }
+}
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index b34a8a6e700..9a879a590e4 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -32,6 +32,8 @@ object BuildGenUtil {
        |
        |${renderJavacOptions(javacOptions)}
        |
+       |${renderScalacOptions(scalacOptions)}
+       |
        |${renderPomSettings(renderIrPom(pomSettings))}
        |
        |${renderPublishVersion(publishVersion)}
@@ -83,6 +85,8 @@ object BuildGenUtil {
        |
        |${renderJavacOptions(javacOptions)}
        |
+       |${renderScalacOptions(scalacOptions)}
+       |
        |${renderRepositories(repositories)}
        |
        |${renderBomIvyDeps(scopedDeps.mainBomIvyDeps)}
@@ -127,7 +131,12 @@ object BuildGenUtil {
       isNested: Boolean,
       packagesSize: Int
   ): SortedSet[String] = {
-    scala.collection.immutable.SortedSet("mill._", "mill.javalib._", "mill.javalib.publish._") ++
+    scala.collection.immutable.SortedSet(
+      "mill._",
+      "mill.javalib._",
+      "mill.javalib.publish._",
+      "mill.scalalib.SbtModule"
+    ) ++
       (if (isNested) baseModule.map(name => s"$$file.$name")
        else if (packagesSize > 1) Seq("$packages._")
        else None)
@@ -379,6 +388,14 @@ object BuildGenUtil {
       args.iterator.map(escape)
     )
 
+  def renderScalacOptions(args: Option[IterableOnce[String]]): String =
+    args.fold("")(args =>
+      optional(
+        "def scalacOptions = super.scalacOptions() ++ Seq",
+        args.iterator.map(escape)
+      )
+    )
+
   def renderRepositories(args: IterableOnce[String]): String =
     optional(
       "def repositoriesTask = Task.Anon { super.repositoriesTask() ++ Seq(",
@@ -425,7 +442,13 @@ object BuildGenUtil {
   val testModulesByGroup: Map[String, String] = Map(
     "junit" -> "TestModule.Junit4",
     "org.junit.jupiter" -> "TestModule.Junit5",
-    "org.testng" -> "TestModule.TestNg"
+    "org.testng" -> "TestModule.TestNg",
+    "org.scalatest" -> "TestModule.ScalaTest",
+    "org.specs2" -> "TestModule.Specs2",
+    "com.lihaoyi.utest" -> "TestModule.UTest",
+    "org.scalameta" -> "TestModule.Munit",
+    "com.disneystreaming" -> "Weaver",
+    "dev.zio" -> "TestModule.ZioTest"
   )
 
   def writeBuildObject(tree: Tree[Node[BuildObject]]): Unit = {
@@ -453,20 +476,28 @@ object BuildGenUtil {
   }
 
   @mainargs.main
-  case class Config(
+  case class BasicConfig(
       @arg(doc = "name of generated base module trait defining shared settings", short = 'b')
       baseModule: Option[String] = None,
-      @arg(
-        doc = "distribution and version of custom JVM to configure in --base-module",
-        short = 'j'
-      )
-      jvmId: Option[String] = None,
       @arg(doc = "name of generated nested test module", short = 't')
       testModule: String = "test",
       @arg(doc = "name of generated companion object defining dependency constants", short = 'd')
       depsObject: Option[String] = None,
       @arg(doc = "merge build files generated for a multi-module build", short = 'm')
-      merge: Flag = Flag(),
+      merge: Flag = Flag()
+  )
+  object BasicConfig {
+    implicit def parser: mainargs.ParserForClass[BasicConfig] = mainargs.ParserForClass[BasicConfig]
+  }
+  // TODO alternative names: `MavenAndGradleConfig`, `MavenAndGradleSharedConfig`
+  @mainargs.main
+  case class Config(
+      basicConfig: BasicConfig,
+      @arg(
+        doc = "distribution and version of custom JVM to configure in --base-module",
+        short = 'j'
+      )
+      jvmId: Option[String] = None,
       @arg(doc = "capture Maven publish properties", short = 'p')
       publishProperties: Flag = Flag()
   )
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index e43d81e0d29..d835498b66c 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -41,6 +41,7 @@ case class IrTrait(
     baseModule: String,
     moduleSupertypes: Seq[String],
     javacOptions: Seq[String],
+    scalacOptions: Option[Seq[String]],
     pomSettings: IrPom,
     publishVersion: String,
     publishProperties: Seq[(String, String)],
@@ -75,6 +76,7 @@ case class IrLicense(
     distribution: String = "repo"
 )
 
+// TODO Consider renaming to `IrModule(Build)` to disambiguate? sbt, for example, uses `ThisBuild` and `buildSettings` to refer to the whole build.
 case class IrBuild(
     scopedDeps: IrScopedDeps,
     testModule: String,
@@ -82,6 +84,7 @@ case class IrBuild(
     dirs: Seq[String],
     repositories: Seq[String],
     javacOptions: Seq[String],
+    scalacOptions: Option[Seq[String]],
     projectName: String,
     pomSettings: IrPom,
     publishVersion: String,
@@ -93,6 +96,7 @@ case class IrBuild(
 )
 
 case class IrScopedDeps(
+    // TODO The type is `Seq` and this is deduplicated and sorted in `BuildGenUtil`. Make the type `SortedMap` here for consistency?
     namedIvyDeps: Seq[(String, String)] = Nil,
     mainBomIvyDeps: SortedSet[String] = SortedSet(),
     mainIvyDeps: SortedSet[String] = SortedSet(),
@@ -111,9 +115,18 @@ case class IrScopedDeps(
 
 case class IrBaseInfo(
     javacOptions: Seq[String] = Nil,
+    scalacOptions : Option[Seq[String]] = None,
     repositories: Seq[String] = Nil,
     noPom: Boolean = true,
     publishVersion: String = "",
     publishProperties: Seq[(String, String)] = Nil,
     moduleTypedef: IrTrait = null
 )
+
+sealed class IrDependencyType
+object IrDependencyType {
+  case object Default extends IrDependencyType
+  case object Test extends IrDependencyType
+  case object Compile extends IrDependencyType
+  case object Run extends IrDependencyType
+}
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index dfdd81cb72b..2cfdb7fdeaf 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -39,7 +39,7 @@ import scala.jdk.CollectionConverters.*
  *  - non-Java sources
  */
 @mill.api.internal
-object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
+object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectModel, JavaModel.Dep] {
   type C = Config
 
   def main(args: Array[String]): Unit = {
@@ -75,7 +75,7 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
           (Node(dirs, project), children)
         }
 
-        convertWriteOut(cfg, cfg.shared, input)
+        convertWriteOut(cfg, cfg.shared.basicConfig, input)
 
         println("converted Gradle build to Mill")
       } finally connection.close()
@@ -124,6 +124,7 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
         Option.when(null != project.maven().pom()) { "PublishModule" }
 
     val javacOptions = getJavacOptions(project)
+    val scalacOptions = None
     val repos = getRepositories(project)
     val pomSettings = extractPomSettings(project)
     val publishVersion = getPublishVersion(project)
@@ -134,13 +135,22 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
       baseModule,
       supertypes,
       javacOptions,
+      scalacOptions,
       pomSettings,
       publishVersion,
       publishProperties,
       repos
     )
 
-    IrBaseInfo(javacOptions, repos, pomSettings == null, publishVersion, Seq.empty, typedef)
+    IrBaseInfo(
+      javacOptions,
+      scalacOptions,
+      repos,
+      pomSettings == null,
+      publishVersion,
+      Seq.empty,
+      typedef
+    )
   }
 
   override def extractIrBuild(
@@ -154,11 +164,12 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
     val version = getPublishVersion(project)
     IrBuild(
       scopedDeps = scopedDeps,
-      testModule = cfg.shared.testModule,
+      testModule = cfg.shared.basicConfig.testModule,
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(project).diff(baseInfo.repositories),
       javacOptions = getJavacOptions(project).diff(baseInfo.javacOptions),
+      scalacOptions = None,
       projectName = getArtifactId(project),
       pomSettings = if (baseInfo.noPom) extractPomSettings(project) else null,
       publishVersion = if (version == baseInfo.publishVersion) null else version,
@@ -173,7 +184,7 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
   }
 
   def getModuleSupertypes(cfg: Config): Seq[String] =
-    Seq(cfg.shared.baseModule.getOrElse("MavenModule"))
+    Seq(cfg.shared.basicConfig.baseModule.getOrElse("MavenModule"))
 
   def getPackage(project: ProjectModel): (String, String, String) = {
     (project.group(), project.name(), project.version())
@@ -183,13 +194,12 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
 
   def getMillSourcePath(model: ProjectModel): Path = os.Path(model.directory())
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] = {
+  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] =
     Seq("RootModule") ++
       Option.when(null != build.value.maven().pom() && baseInfo.noPom) { "PublishModule" } ++
       Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
         getModuleSupertypes(cfg)
       }.toSeq.flatten
-  }
 
   def groupArtifactVersion(dep: JavaModel.Dep): (String, String, String) =
     (dep.group(), dep.name(), dep.version())
@@ -250,6 +260,7 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
     }
   }
 
+  // TODO consider renaming to `extractConfigurationDeps` as Gradle calls them configurations instead of scopes
   def extractScopedDeps(
       project: ProjectModel,
       packages: PartialFunction[(String, String, String), String],
@@ -260,7 +271,7 @@ object GradleBuildGenMain extends BuildGenBase[ProjectModel, JavaModel.Dep] {
     val _java = project._java()
     if (null != _java) {
       val ivyDep: JavaModel.Dep => String =
-        cfg.shared.depsObject.fold(interpIvy(_)) { objName => dep =>
+        cfg.shared.basicConfig.depsObject.fold(interpIvy(_)) { objName => dep =>
           val depName = s"`${dep.group()}:${dep.name()}`"
           sd = sd.copy(namedIvyDeps = sd.namedIvyDeps :+ (depName, interpIvy(dep)))
           s"$objName.$depName"
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index a8d9c0719a9..7edc0add46a 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -36,7 +36,7 @@ import scala.jdk.CollectionConverters.*
  *  - build profiles
  */
 @mill.api.internal
-object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
+object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Dependency] {
   type C = Config
 
   def main(args: Array[String]): Unit = {
@@ -54,7 +54,7 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
       (Node(dirs, model), model.getModules.iterator().asScala.map(dirs :+ _))
     }
 
-    convertWriteOut(cfg, cfg.shared, input)
+    convertWriteOut(cfg, cfg.shared.basicConfig, input)
 
     println("converted Maven build to Mill")
   }
@@ -67,7 +67,8 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
   ): IrBaseInfo = {
     val model = input.node.value
     val javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model)
-    val repositores = getRepositories(model)
+    val scalacOptions = None
+    val repositories = getRepositories(model)
     val pomSettings = extractPomSettings(model)
     val publishVersion = model.getVersion
     val publishProperties = getPublishProperties(model, cfg.shared)
@@ -77,13 +78,22 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
       baseModule,
       getModuleSupertypes(cfg),
       javacOptions,
+      scalacOptions,
       pomSettings,
       publishVersion,
       publishProperties,
       getRepositories(model)
     )
 
-    IrBaseInfo(javacOptions, repositores, noPom = false, publishVersion, publishProperties, typedef)
+    IrBaseInfo(
+      javacOptions,
+      scalacOptions,
+      repositories,
+      noPom = false,
+      publishVersion,
+      publishProperties,
+      typedef
+    )
   }
 
   override def extractIrBuild(
@@ -97,11 +107,12 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
     val version = model.getVersion
     IrBuild(
       scopedDeps = scopedDeps,
-      testModule = cfg.shared.testModule,
+      testModule = cfg.shared.basicConfig.testModule,
       hasTest = os.exists(getMillSourcePath(model) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(model),
       javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model).diff(baseInfo.javacOptions),
+      scalacOptions = None,
       projectName = getArtifactId(model),
       pomSettings = if (baseInfo.noPom) extractPomSettings(model) else null,
       publishVersion = if (version == baseInfo.publishVersion) null else version,
@@ -127,10 +138,9 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
 
   def getMillSourcePath(model: Model): Path = os.Path(model.getProjectDirectory)
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] = {
+  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] =
     Seq("RootModule") ++
-      cfg.shared.baseModule.fold(getModuleSupertypes(cfg))(Seq(_))
-  }
+      cfg.shared.basicConfig.baseModule.fold(getModuleSupertypes(cfg))(Seq(_))
 
   def processResources(
       input: java.util.List[org.apache.maven.model.Resource],
@@ -205,7 +215,7 @@ object MavenBuildGenMain extends BuildGenBase[Model, Dependency] {
 
     val hasTest = os.exists(os.Path(model.getProjectDirectory) / "src/test")
     val ivyDep: Dependency => String = {
-      cfg.shared.depsObject.fold(interpIvy(_)) { objName => dep =>
+      cfg.shared.basicConfig.depsObject.fold(interpIvy(_)) { objName => dep =>
         {
           val depName = s"`${dep.getGroupId}:${dep.getArtifactId}`"
           sd = sd.copy(namedIvyDeps = sd.namedIvyDeps :+ (depName, interpIvy(dep)))
diff --git a/main/init/package.mill b/main/init/package.mill
index 91d51a866ea..90ff867d9c4 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -1,7 +1,6 @@
 package build.main.init
 
 import mill._
-import mill.scalalib.CrossScalaModule
 
 object `package` extends RootModule with build.MillPublishScalaModule {
 
@@ -63,8 +62,16 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   }
 
   object buildgen extends build.MillPublishScalaModule {
-    def moduleDeps = Seq(build.runner)
+    def moduleDeps = Seq(build.runner /*, tree(build.Deps.scalaVersion)*/ )
     def testModuleDeps = super.testModuleDeps ++ Seq(build.scalalib)
+
+    // I tried moving `Tree` into this module, but it doesn't compile with Scala 2.12.20.
+    /*
+    object tree extends Cross[TreeModule](build.Deps.sbtScalaVersion212, build.Deps.scalaVersion)
+    trait TreeModule extends build.MillPublishCrossScalaModule {
+      def ivyDeps = Agg(build.Deps.upickle)
+    }
+     */
   }
   object gradle extends build.MillPublishScalaModule {
     def moduleDeps = Seq(buildgen)
@@ -90,27 +97,33 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   object sbt extends build.MillPublishScalaModule {
     def moduleDeps = Seq(buildgen, models(build.Deps.scalaVersion))
 
+    val sbtPluginProjectPath = millModuleBasePath.value / "sbt-mill-init-export-build"
+
+    def sbtPluginProjectSource = Task.Source { sbtPluginProjectPath }
+
     // generateSbtPluginJar
     def sbtPluginJarResources = Task {
       models(build.Deps.sbtScalaVersion212).publishLocal()()
 
+      sbtPluginProjectSource()
+
       import scala.sys.process._
-      val sbtProjectPath = millModuleBasePath.value / "sbt-mill-init-generate-project-tree"
       val version = build.millVersion()
       if (
         Process(
           // The version is passed to the sbt build so it correctly resolves the "models" dependency version and sets its own version.
           s"""sbt 'set version := "$version"' assembly""",
-          sbtProjectPath.toIO
+          sbtPluginProjectPath.toIO
         ).! != 0
       )
         throw new RuntimeException(
-          "fail to run `sbt assembly` in the \"sbt-mill-init-generate-project-tree\" sbt project."
+          "Failed to run `sbt assembly` in the \"sbt-mill-init-export-build\" sbt project. " +
+            "Check if the project builds correctly and if you have sbt available on your system, and install it if you don't."
         )
 
       os.copy(
-        sbtProjectPath / "target" / "scala-2.12" / "sbt-1.0" / s"sbt-mill-init-generate-project-tree-assembly-$version.jar",
-        Task.dest / "sbt-mill-init-generate-project-tree-assembly.jar"
+        sbtPluginProjectPath / "target" / "scala-2.12" / "sbt-1.0" / s"sbt-mill-init-export-build-assembly-$version.jar",
+        Task.dest / "sbt-mill-init-export-build-assembly.jar"
       )
       PathRef(Task.dest)
     }
@@ -121,8 +134,10 @@ object `package` extends RootModule with build.MillPublishScalaModule {
     // An SBT plugin is built with Scala 2.12. See https://www.scala-sbt.org/1.x/docs/Plugins.html#Creating+an+auto+plugin.
     object models
         extends Cross[ModelsModule](build.Deps.sbtScalaVersion212, build.Deps.scalaVersion)
-    trait ModelsModule extends build.MillPublishJavaModule with CrossScalaModule {
+    trait ModelsModule extends build.MillPublishCrossScalaModule {
+      // def moduleDeps = Seq(buildgen.tree())
       def ivyDeps = Agg(build.Deps.upickle)
+      def compileIvyDeps = Agg(build.Deps.sbt) // for definition references only
     }
   }
 }
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 983aa85b46b..6c39a33bf5f 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -1,8 +1,307 @@
 package mill.main.sbt
 
-import upickle.default.{ReadWriter => RW, macroRW}
+import mill.main.sbt.BuildPublicationInfo.License
+import mill.main.sbt.Models.URL
+import sbt.Keys
+import upickle.default.{macroRW, ReadWriter => RW}
 
-case class ProjectTree()
-object ProjectTree {
-  implicit val rw: RW[ProjectTree] = macroRW
+object Models {
+  type URL = String
+
+  // TODO Remove. This seems not supported.
+
+  type Id[X] = X // not working with uPickle
+  /*object Id {
+    //implicit def rw[T](tRw : RW[T]) : RW[Id[T]] = tRw
+    implicit def rw[T: RW]: RW[Id[T]] = macroRW
+  }*/
+}
+
+// TODO Remove. Not used.
+/**
+ * A wrapper added because [[Models.Id]] does not work with uPickle.
+ * @param wrappedValue named this way in order not to conflict with [[sbt.std.MacroValue.value]]
+ */
+case class Wrapper[+A](wrappedValue: A) extends AnyVal {
+  def map[B](f: A => B): Wrapper[B] = Wrapper(f(wrappedValue))
+}
+object Wrapper {
+  import scala.language.implicitConversions
+  implicit def to[A](value: A): Wrapper[A] =
+    Wrapper(value)
+  implicit def from[A](wrapper: Wrapper[A]): A =
+    wrapper.wrappedValue
+
+  implicit def rw[T: RW]: RW[Wrapper[T]] = macroRW
+}
+
+case class BuildExport(
+    /** @see [[sbt.AutoPlugin.buildSettings]] and [[sbt.AutoPlugin.globalSettings]] */
+    defaultBuildInfo: BuildInfo,
+    projects: Seq[Project]
+)
+object BuildExport {
+  implicit val rw: RW[BuildExport] = macroRW
+}
+
+// TODO remove these plain ones
+
+case class PlainBuildInfo(
+    buildPublicationInfo: PlainBuildPublicationInfo,
+    /** @see [[Keys.javacOptions]] */
+    javacOptions: Seq[String],
+    /** @see [[Keys.resolvers]] */
+    resolvers: Seq[Resolver]
+)
+object PlainBuildInfo {
+  implicit val rw: RW[PlainBuildInfo] = macroRW
+}
+
+case class PlainBuildPublicationInfo(
+    /** @see [[Keys.description]] */
+    description: String,
+    /**
+     * corresponds to `url` in POM
+     *
+     * @see [[Keys.homepage]]
+     */
+    homepage: Option[String],
+    /** @see [[Keys.licenses]] */
+    licenses: Seq[License],
+    // organization: Option[String],
+    /*
+                                      /**
+     * corresponds to Maven's `organization` in POM
+     *
+     * @see [[Keys.organization]]
+     */
+                                      organizationName: String,
+     */
+    /**
+     * corresponds to `organizationUrl` in POM
+     *
+     * @see [[Keys.organizationHomepage]]
+     */
+    organizationHomepage: Option[String],
+    /** @see [[Keys.developers]] */
+    developers: Seq[Developer],
+    /** @see [[Keys.scmInfo]] */
+    scmInfo: Option[ScmInfo]
+)
+object PlainBuildPublicationInfo {
+  implicit val rw: RW[PlainBuildPublicationInfo] = macroRW
+
+  /** @see [[sbt.librarymanagement.License]] */
+  type License = (String, URL)
+}
+
+/*
+TODO I used higher-kinded types here along with some higher-rank types (`GetValueFn` and `MapFn`) in the sbt plugin,
+ because I first thought that the default build info's members don't need to be wrapped with `Option` while the project build info's members do,
+ and we can reuse some more code this way,
+ but it turns out that both kinds have to be wrapped with `Option` and the abstraction doesn't work with the sbt `value` macros.
+ Most likely we can just replace `F` with `Option` in them and remove the `TC` suffixes,
+ resulting in `mill.main.sbt.BuildInfo` below,
+ unless they can possibly provide more extensibility, which is unlikely as I think now.
+ See other related definitions such as `Id`, `Wrapper`,
+ `getBuildInfo[F[_]](ref: Reference, getValue: GetValueFn[F], map: MapFn[F]): BuildInfoTC[F]`, `GetValueFn`, and `MapFn`.
+ */
+
+case class BuildInfoTC[F[_]](
+    buildPublicationInfo: BuildPublicationInfoTC[F],
+    /** @see [[Keys.javacOptions]] */
+    javacOptions: F[Seq[String]],
+    /** @see [[Keys.scalacOptions]] */
+    scalacOptions: F[Seq[String]],
+    /** @see [[Keys.resolvers]] */
+    resolvers: F[Seq[Resolver]]
+)
+object BuildInfoTC {
+  type BuildInfo = BuildInfoTC[Wrapper]
+  implicit val wrapperRw: RW[BuildInfo] = macroRW
+  type OptionBuildInfo = BuildInfoTC[Option]
+  implicit val optionRw: RW[OptionBuildInfo] = macroRW
+}
+
+case class BuildPublicationInfoTC[F[_]](
+    /** @see [[Keys.description]] */
+    description: F[String],
+    /**
+     * corresponds to `url` in POM
+     *
+     * @see [[Keys.homepage]]
+     */
+    homepage: F[Option[String]],
+    /** @see [[Keys.licenses]] */
+    licenses: F[Seq[PlainBuildPublicationInfo.License]],
+    // organization: Option[String],
+    /*
+    /**
+     * corresponds to Maven's `organization` in POM
+     *
+     * @see [[Keys.organization]]
+     */
+    organizationName: F[String],
+     */
+    /**
+     * corresponds to `organizationUrl` in POM
+     *
+     * @see [[Keys.organizationHomepage]]
+     */
+    organizationHomepage: F[Option[String]],
+    /** @see [[Keys.developers]] */
+    developers: F[Seq[Developer]],
+    /** @see [[Keys.scmInfo]] */
+    scmInfo: F[Option[ScmInfo]]
+)
+object BuildPublicationInfoTC {
+
+  /** @see [[sbt.librarymanagement.License]] */
+  type License = (String, URL)
+
+  /*
+  // This does not work: "could not find implicit value for parameter e: upickle.default.Reader[F[String]]".
+  implicit def rw[F[_]]: RW[BuildPublicationInfoTC[F]] = macroRW
+   */
+  /*
+  // This does not work: "could not find implicit value for parameter e: upickle.default.Reader[mill.main.sbt.Models.Id[Seq[mill.main.sbt.BuildPublicationInfo.License]]]".
+  type BuildPublicationInfo = BuildPublicationInfoTC[Id]
+  implicit val IdRw: RW[BuildPublicationInfo] = macroRW
+   */
+  type BuildPublicationInfo = BuildPublicationInfoTC[Wrapper]
+  implicit val wrapperRw: RW[BuildPublicationInfo] = macroRW
+  type OptionBuildPublicationInfo = BuildPublicationInfoTC[Option]
+  implicit val optionRw: RW[OptionBuildPublicationInfo] = macroRW
+}
+
+case class BuildInfo(
+    buildPublicationInfo: BuildPublicationInfo,
+    /** @see [[Keys.javacOptions]] */
+    javacOptions: Option[Seq[String]],
+    /** @see [[Keys.scalacOptions]] */
+    scalacOptions: Option[Seq[String]],
+    /** @see [[Keys.resolvers]] */
+    resolvers: Option[Seq[Resolver]]
+)
+object BuildInfo {
+  implicit val rw: RW[BuildInfo] = macroRW
+}
+
+/**
+ * Members ordered by their order in [[Keys]].
+ */
+case class BuildPublicationInfo(
+    /** @see [[Keys.description]] */
+    description: Option[String],
+    /**
+     * corresponds to `url` in POM
+     *
+     * @see [[Keys.homepage]]
+     */
+    homepage: Option[Option[String]],
+    /** @see [[Keys.licenses]] */
+    licenses: Option[Seq[PlainBuildPublicationInfo.License]],
+    /**
+     * corresponds to `groupId` in POM and Mill's `PomSettings.organization`
+     *
+     * @see [[Keys.organization]]
+     */
+    organization: Option[String],
+    // not needed
+    /*
+    /**
+     * corresponds to Maven's `organization` in POM
+     *
+     * @see [[Keys.organizationName]]
+     */
+    organizationName: Option[String],
+     */
+    /**
+     * corresponds to `organizationUrl` in POM
+     *
+     * @see [[Keys.organizationHomepage]]
+     */
+    organizationHomepage: Option[Option[String]],
+    /** @see [[Keys.developers]] */
+    developers: Option[Seq[Developer]],
+    /** @see [[Keys.scmInfo]] */
+    scmInfo: Option[Option[ScmInfo]],
+    /** @see [[Keys.version]] */
+    version: Option[String]
+)
+object BuildPublicationInfo {
+
+  /** @see [[sbt.librarymanagement.License]] */
+  type License = (String, URL)
+
+  implicit val rw: RW[BuildPublicationInfo] = macroRW
+}
+
+/**
+ * @see [[sbt.librarymanagement.ScmInfo]]
+ */
+case class ScmInfo(
+    browseUrl: URL,
+    connection: String,
+    devConnection: Option[String]
+)
+object ScmInfo {
+  implicit val rw: RW[ScmInfo] = macroRW
+}
+
+/**
+ * @see [[sbt.librarymanagement.Developer]]
+ */
+case class Developer(id: String, name: String, email: String, url: URL)
+object Developer {
+  implicit val rw: RW[Developer] = macroRW
+}
+
+/**
+ * Only Maven repositories are supported now.
+ * @see [[sbt.librarymanagement.Resolver]]
+ */
+case class Resolver(root: String)
+object Resolver {
+  implicit val rw: RW[Resolver] = macroRW
+}
+
+case class Project(
+    // organization: String, // `groupId` in Maven, moved inside `buildInfo`
+    name: String, // `artifactId` in Maven
+    // version: String, // `groupId` in Maven, moved inside `buildInfo`
+    // dirs: ProjectDirs, // relative
+    projectDirectory: String,
+    buildInfo: BuildInfo,
+    // dependencyConfigurations: Seq[DependencyConfiguration] // TODO remove
+    allDependencies: Seq[Dependency]
+)
+object Project {
+  implicit val rw: RW[Project] = macroRW
+
+  // TODO Remove. Not used.
+  type ProjectDirs = Seq[String]
+}
+
+// TODO Remove. For an old implementation of retrieving `Configuration / allDependencies` that doesn't work.
+case class DependencyConfiguration(
+    id: String,
+    allDependencies: Seq[Dependency]
+    /*, projectDependencies: Seq[ProjectDirs], libraryDependencies: Seq[LibraryDependency]*/
+)
+object DependencyConfiguration {
+  implicit val rw: RW[DependencyConfiguration] = macroRW
+}
+
+case class Dependency(
+    organization: String, // `groupId` in Maven
+    name: String, // `artifactId` in Maven
+    crossVersion: Boolean = false,
+    revision: String,
+    configurations: Option[String]
+    // BOM seems not supported by sbt. See https://stackoverflow.com/questions/42032303/how-do-i-use-a-maven-bom-bill-of-materials-to-manage-my-dependencies-in-sbt.
+    // isBom : Boolean = false
+)
+object Dependency {
+  implicit val rw: RW[Dependency] = macroRW
 }
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore b/main/init/sbt/sbt-mill-init-export-build/.gitignore
similarity index 100%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/.gitignore
rename to main/init/sbt/sbt-mill-init-export-build/.gitignore
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/README.md b/main/init/sbt/sbt-mill-init-export-build/README.md
similarity index 84%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/README.md
rename to main/init/sbt/sbt-mill-init-export-build/README.md
index 55e348119f8..344d9991bac 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/README.md
+++ b/main/init/sbt/sbt-mill-init-export-build/README.md
@@ -5,6 +5,6 @@ An sbt plugin to generate the project tree for `mill init`
 ## Working on this project
 
 Make sure you are on the SNAPSHOT version of Mill,
-and run `./mill "main.init.sbt.models[2.12.20].publishLocal"`,
+and run `./mill "main.init.sbt.models[2.12.20].publishLocal"`
 to publish the models to Ivy's local repository before working on this project.
 Then open this directory as a separate IntelliJ IDEA project as this is an sbt project.
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt b/main/init/sbt/sbt-mill-init-export-build/build.sbt
similarity index 80%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
rename to main/init/sbt/sbt-mill-init-export-build/build.sbt
index 9ee673f5ba5..9cbfecbaca8 100644
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/build.sbt
+++ b/main/init/sbt/sbt-mill-init-export-build/build.sbt
@@ -1,5 +1,4 @@
-
-name := """sbt-mill-init-generate-project-tree"""
+name := """sbt-mill-init-export-build"""
 organization := "com.lihaoyi"
 version := "SNAPSHOT"
 
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties b/main/init/sbt/sbt-mill-init-export-build/project/build.properties
similarity index 100%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/project/build.properties
rename to main/init/sbt/sbt-mill-init-export-build/project/build.properties
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt b/main/init/sbt/sbt-mill-init-export-build/project/plugins.sbt
similarity index 100%
rename from main/init/sbt/sbt-mill-init-generate-project-tree/project/plugins.sbt
rename to main/init/sbt/sbt-mill-init-export-build/project/plugins.sbt
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
new file mode 100644
index 00000000000..64c6e71d4c4
--- /dev/null
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -0,0 +1,247 @@
+package mill.main.sbt
+
+import sbt.Keys.*
+import sbt.Project.extract
+import sbt.io.IO
+import sbt.librarymanagement.Disabled
+import sbt.{Def, Developer as _, Project as _, Resolver as _, ScmInfo as _, *}
+import upickle.default.*
+
+import java.io.File
+import scala.language.higherKinds
+
+object ExportBuildPlugin extends AutoPlugin {
+  override def trigger = allRequirements
+  // override def requires = ??? // defaults to `JvmPlugin`
+
+  object autoImport {
+    val millInitBuildInfo = taskKey[BuildInfo](
+      "get the `mill.main.sbt.BuildInfo` model of this build or this project"
+    )
+    // TODO Remove. No longer used.
+    val millInitDependencyConfiguration = taskKey[DependencyConfiguration](
+      "get the `mill.main.sbt.DependencyConfiguration` model of this project and configuration"
+    )
+    val millInitAllDependencies = taskKey[Seq[Dependency]](
+      "get the all the `mill.main.sbt.Dependency`s of this project"
+    )
+    val millInitProject = taskKey[Project]("get the `mill.main.sbt.Project` model of this project")
+    val millInitExportBuild = taskKey[File]("export the build in a JSON file for `mill init`")
+  }
+
+  // TODO `getBuildInfo` along with `MapFn` and `GetValueFn` does not work with the `value` macro. Remove.
+
+  trait MapFn[F[_]] {
+    // def apply[A, B](fa : F[A], f: A => B): F[B] // Type inference doesn't work well with this.
+    def apply[A, B](fa: F[A])(f: A => B): F[B]
+  }
+
+  trait GetValueFn[F[_]] {
+    def apply[T](key: SettingKey[T]): F[T]
+
+    def apply[T](key: TaskKey[T]): F[T]
+  }
+
+  def getBuildInfo[F[_]](ref: Reference, getValue: GetValueFn[F], map: MapFn[F]): BuildInfoTC[F] =
+    BuildInfoTC(
+      BuildPublicationInfoTC(
+        getValue(ref / description),
+        map(getValue(ref / homepage))(_.map(_.toExternalForm)),
+        map(getValue(ref / licenses))(_.map { case (name, url) => (name, url.toExternalForm) }),
+        //getValue(ref / organizationName), // not needed
+        map(getValue(ref / organizationHomepage))(_.map(_.toExternalForm)),
+        map(getValue(ref / developers))(_.map(developer =>
+          Developer(developer.id, developer.name, developer.email, developer.url.toExternalForm)
+        )),
+        map(getValue(ref / scmInfo))(_.map(scmInfo =>
+          ScmInfo(scmInfo.browseUrl.toExternalForm, scmInfo.connection, scmInfo.devConnection)
+        ))
+      ),
+      getValue(ref / javacOptions),
+      getValue(ref / scalacOptions),
+      map(getValue(ref / resolvers))(_.flatMap {
+        case mavenRepository: MavenRepository => Some(Resolver(mavenRepository.root))
+        case resolver =>
+          println(s"A `Resolver` which is not a `MavenRepository` is skipped: $resolver")
+          None
+      })
+    )
+
+  import autoImport.*
+
+  val buildInfoSetting = millInitBuildInfo := BuildInfo(
+    BuildPublicationInfo(
+      description.?.value,
+      homepage.?.value.map(_.map(_.toExternalForm)),
+      licenses.?.value.map(_.map { case (name, url) =>
+        (name, url.toExternalForm)
+      }),
+      organization.?.value,
+      //organizationName.?.value, // not needed
+      organizationHomepage.?.value.map(_.map(_.toExternalForm)),
+      developers.?.value.map(_.map(developer =>
+        Developer(developer.id, developer.name, developer.email, developer.url.toExternalForm)
+      )),
+      scmInfo.?.value.map(_.map(scmInfo =>
+        ScmInfo(scmInfo.browseUrl.toExternalForm, scmInfo.connection, scmInfo.devConnection)
+      )),
+      version.?.value
+    ),
+    javacOptions.?.value,
+    scalacOptions.?.value,
+    resolvers.?.value.map(_.flatMap {
+      case mavenRepository: MavenRepository => Some(Resolver(mavenRepository.root))
+      case resolver =>
+        println(s"A `Resolver` which is not a `MavenRepository` is skipped: $resolver")
+        None
+    })
+  )
+
+  override lazy val buildSettings: Seq[Def.Setting[?]] = Seq(
+    buildInfoSetting
+  )
+
+  // TODO Remove. For an old implementation that depends on retrieving `configuration / allDependencies` which doesn't work.
+  private val neededConfigurations = Seq(Compile, Test, Runtime, Default, Provided, Optional)
+
+  // TODO Remove. No longer used. Replaced by `millInitAllDependencies`.
+  val millInitDependencyConfigurationSetting =
+    millInitDependencyConfiguration := DependencyConfiguration(
+      configuration.value.id,
+
+      /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
+      /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
+        Dependency(
+          moduleID.organization,
+          moduleID.name,
+          moduleID.crossVersion match {
+            case Disabled => false
+            case _: Binary => true
+            case crossVersion =>
+              println(s"Unsupported `CrossVersion`: $crossVersion")
+              false
+          },
+          moduleID.revision,
+          moduleID.configurations
+        )
+      }
+    )
+
+  override lazy val projectSettings: Seq[Setting[?]] = Seq(
+    Seq(buildInfoSetting),
+    // TODO Remove. For an old implementation that depends on `configuration / allDependencies` which doesn't work.
+    neededConfigurations.flatMap(configuration => inConfig(configuration)(Seq(millInitDependencyConfigurationSetting))),
+    Seq(
+      millInitAllDependencies := {
+        /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
+        /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
+          Dependency(
+            moduleID.organization,
+            moduleID.name,
+            moduleID.crossVersion match {
+              case Disabled => false
+              case _: Binary => true
+              case crossVersion =>
+                println(s"Unsupported `CrossVersion`: $crossVersion")
+                false
+            },
+            moduleID.revision,
+            moduleID.configurations
+          )
+        }
+      },
+      millInitProject := {
+        // TODO remove
+        val extracted = extract(state.value) // TODO move to a separate task if used
+        Project(
+          //organization.value,
+          name.value,
+          //version.value,
+          //baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
+          baseDirectory.value.getPath,
+          // TODO remove old implementation
+          /*
+          getBuildInfo[Option](
+            ThisProject,
+            new GetValueFn[Option] {
+              override def apply[T](key: SettingKey[T]): Option[T] = extracted.getOpt(key)
+
+              override def apply[T](key: TaskKey[T]): Option[T] =
+                ??? // extracted.getOpt(key).map(_.value)
+            },
+            new MapFn[Option] {
+              override def apply[A, B](fa: Option[A])(f: A => B): Option[B] = fa.map(f)
+            }
+          )
+           */
+          {
+            // keep the project `BuildInfo` members only when they are different
+            val defaultBi = (ThisBuild / millInitBuildInfo).value
+            val projectBi = millInitBuildInfo.value
+            import projectBi.*
+            BuildInfo({
+              val defaultBpi = defaultBi.buildPublicationInfo
+              import projectBi.buildPublicationInfo.*
+              BuildPublicationInfo(
+                if (description != defaultBpi.description) description else None,
+                if (homepage != defaultBpi.homepage) homepage else None,
+                if (licenses != defaultBpi.licenses) licenses else None,
+                if (organization != defaultBpi.organization) organization else None,
+                //if (organizationName != defaultBpi.organizationName) organizationName else None, // not needed
+                if (organizationHomepage != defaultBpi.organizationHomepage) organizationHomepage else None,
+                if (developers != defaultBpi.developers) developers else None,
+                if (scmInfo != defaultBpi.scmInfo) scmInfo else None,
+                if (version != defaultBpi.version) version else None
+              )
+            },
+              if (javacOptions != defaultBi.javacOptions) javacOptions else None,
+              if (scalacOptions != defaultBi.scalacOptions) scalacOptions else None,
+              if (resolvers != defaultBi.resolvers) resolvers else None
+            )
+          },
+          {
+            // TODO Remove. For an old implementation that depends on retrieving `configuration / allDependencies` which doesn't work.
+            millInitDependencyConfiguration.all(
+              ScopeFilter(configurations = inConfigurations(neededConfigurations *))
+            ).value
+            millInitAllDependencies.value
+          }
+        )
+      },
+      // `target.value` doesn't work in `globalSettings` and `buildSettings`, so this is added to `projectSettings.
+      millInitExportBuild := {
+        // TODO This does not work with the `value` macro. Remove.
+        /*
+        val defaultBuildInfo = getBuildInfo[Wrapper](
+          ThisBuild,
+          new GetValueFn[Wrapper] {
+            override def apply[T](key: SettingKey[T]): Wrapper[T] =
+              ??? // Wrapper(key.value) // Could not find proxy
+            override def apply[T](key: TaskKey[T]): Wrapper[T] =
+              ??? // Wrapper(key.value) // Could not find proxy
+          },
+          new MapFn[Wrapper] {
+            override def apply[A, B](fa: Wrapper[A])(f: A => B): Wrapper[B] = fa.map(f)
+          }
+        )
+         */
+
+        val defaultBuildInfo = (ThisBuild / millInitBuildInfo).value
+
+        // TODO remove the old implementation code
+        // `(projectRef / ...)` can't be used directly here due to macro limitations: "java.lang.IllegalArgumentException: Could not find proxy for projectRef: sbt.ProjectRef in ..."
+        /*
+        val allProjectPairs = buildStructure.value.allProjectPairs
+        val projects = allProjectPairs.map { case (resolvedProject, projectRef) => ??? }
+         */
+
+        val projects = millInitProject.all(ScopeFilter(inAnyProject)).value
+
+        val buildExport = BuildExport(defaultBuildInfo, projects)
+
+        val outputFile = target.value / "mill-init-build-export.json"
+        IO.write(outputFile, write(buildExport))
+        outputFile
+      }
+    )).flatten
+}
diff --git a/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala b/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
deleted file mode 100644
index 3fe31be4d2e..00000000000
--- a/main/init/sbt/sbt-mill-init-generate-project-tree/src/main/scala/mill/main/sbt/ProjectTreePlugin.scala
+++ /dev/null
@@ -1,29 +0,0 @@
-package mill.main.sbt
-
-import sbt.Keys.target
-import sbt.io.syntax.*
-import sbt.{AutoPlugin, IO, Setting, taskKey}
-import upickle.default.*
-
-object ProjectTreePlugin extends AutoPlugin {
-  override def trigger = allRequirements
-  // override def requires = ??? // defaults to `JvmPlugin`
-
-  object autoImport {
-    val millInitGenerateProjectTree = taskKey[File]("generate the project tree for `mill init`")
-  }
-
-  import autoImport.*
-
-  // `target.value` doesn't work in `globalSettings` and `buildSettings`
-  override lazy val projectSettings: Seq[Setting[_]] = Seq(
-    millInitGenerateProjectTree := {
-      // TODO
-      val projectTree = ProjectTree()
-
-      val outputFile = target.value / "mill-init-project-tree.json"
-      IO.write(outputFile, write(projectTree))
-      outputFile
-    }
-  )
-}
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index ff0ea7e3acd..4977a3168d0 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -2,7 +2,12 @@ package mill.main.sbt
 
 import mainargs.{ParserForClass, main}
 import mill.main.buildgen.*
-import mill.main.buildgen.BuildGenUtil.escape
+import mill.main.buildgen.BuildGenUtil.*
+import mill.main.buildgen.IrDependencyType.*
+import os.Path
+
+import scala.collection.View
+import scala.collection.immutable.SortedSet
 
 /**
  * Converts an sbt build to Mill by generating Mill build file(s).
@@ -16,17 +21,24 @@ import mill.main.buildgen.BuildGenUtil.escape
  * The conversion
  *  - handles deeply nested modules
  *  - configures dependencies for configurations:
+ *    - no configuration
  *    - Compile
+ *    - Provided
+ *    - Optional
  *    - Runtime
  *    - Test
- *  - configures testing frameworks:
- *    - JUnit 4
- *    - JUnit 5
- *    - TestNG
- *    - µTest
- *    - ScalaTest
- *    - Specs2
- *    - ScalaCheck
+ *  - configures testing frameworks (@see [[mill.scalalib.TestModule]]):
+ *    - Java:
+ *      - JUnit 4
+ *      - JUnit 5
+ *      - TestNG
+ *    - Scala:
+ *      - ScalaTest
+ *      - Specs2
+ *      - µTest
+ *      - MUnit
+ *      - Weaver
+ *      - ZIOTest
  * ===Limitations===
  * The conversion does not support
  *  - custom configurations
@@ -34,7 +46,7 @@ import mill.main.buildgen.BuildGenUtil.escape
  *  - sources other than Scala on JVM and Java
  */
 @mill.api.internal
-object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
+object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[Node[Project]])] {
   type C = Config
 
   def main(args: Array[String]): Unit = {
@@ -67,62 +79,52 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
 
     println("Running sbt task to generate the project tree")
 
-    val exitCode = Process(
+    Process(
       Seq(
         sbtExecutable,
         s"-addPluginSbtFile=${writeSbtFile().toString}",
-        "millInitGenerateProjectTree"
+        "millInitExportBuild"
       ),
       workspace.toIO
     ).!
 
-    println("Exit code from running the `millInitGenerateProjectTree` sbt task: " + exitCode)
+    // println("Exit code from running the `millInitExportBuild` sbt task: " + exitCode)
 
+    val buildExportPickled = os.read(workspace / "target" / "mill-init-build-export.json")
+    // TODO This is mainly for debugging purposes. Comment out this line if it's unnecessary.
+    println("sbt build export retrieved: " + buildExportPickled)
     import upickle.default.*
-    val projectTree =
-      read[ProjectTree](os.read(workspace / "target" / "mill-init-project-tree.json"))
-    println("Project tree retrieved: " + projectTree)
-
-    /*
-    val connector = GradleConnector.newConnector()
-
-    val args =
-      cfg.shared.jvmId.map { id =>
-        println(s"resolving Java home for jvmId $id")
-        val home = Jvm.resolveJavaHome(id).getOrThrow
-        s"-Dorg.gradle.java.home=$home"
-      } ++ Seq("--init-script", writeGradleInitScript.toString())
-
-    try {
-      println("connecting to Gradle daemon")
-      val connection = connector.forProjectDirectory(workspace.toIO).connect()
-      try {
-        val root = connection.model(classOf[ProjectTree])
-          .withArguments(args.asJava)
-          .get
-
-        val input = Tree.from(root) { tree =>
-          val project = tree.project()
-          val dirs = os.Path(project.directory()).subRelativeTo(workspace).segments
-          val children = tree.children().asScala.sortBy(_.project().name()).iterator
-          (Node(dirs, project), children)
-        }
+    val buildExport = read[BuildExport](buildExportPickled)
+
+    // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
+    val projectNodesByParentDirs: Map[Option[Seq[String]], View[Node[Project]]] =
+      buildExport.projects.view
+        .map(project =>
+          Node(os.Path(project.projectDirectory).subRelativeTo(workspace).segments, project)
+        )
+        .groupBy(node => {
+          val dirs = node.dirs
+          Option.when(dirs.nonEmpty)(dirs.dropRight(1))
+        })
+
+    val input = Tree.from(projectNodesByParentDirs(None).head) { node =>
+      val dirs = node.dirs
+      val children = projectNodesByParentDirs.getOrElse(Some(dirs), Seq.empty)
+      (node, children)
+    }
 
-        convertWriteOut(cfg, cfg.shared, input)
+    convertWriteOut(cfg, cfg.shared, (buildExport.defaultBuildInfo, input))
 
-        println("converted Gradle build to Mill")
-      } finally connection.close()
-    } finally connector.disconnect()
-     */
+    println("converted sbt build to Mill")
   }
 
   private def writeSbtFile(): os.Path = {
     val file = os.temp.dir() / "mill-init.sbt"
     // TODO copy to a temp file if it doesn't work when packaged in a jar
     val sbtPluginJarUrl =
-      getClass.getResource("/sbt-mill-init-generate-project-tree-assembly.jar").toExternalForm
+      getClass.getResource("/sbt-mill-init-export-build-assembly.jar").toExternalForm
     val contents =
-      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-generate-project-tree" % "0.1.0-SNAPSHOT" from ${escape(
+      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-export-build" % "dummy-version" from ${escape(
           sbtPluginJarUrl
         )})
          |""".stripMargin
@@ -130,272 +132,257 @@ object SbtBuildGenMain extends BuildGenBase[IrBuild, String] {
     file
   }
 
-  override def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[IrBuild]): Seq[String] =
-    ???
-
-  override def getBaseInfo(
-      input: Tree[Node[IrBuild]],
-      cfg: Config,
-      baseModule: String,
-      packagesSize: Int
-  ): IrBaseInfo = ???
-
-  override def getPackage(model: IrBuild): (String, String, String) = ???
+  override def getProjectTree(input: (BuildInfo, Tree[Node[Project]])): Tree[Node[Project]] =
+    input._2
 
-  override def getArtifactId(model: IrBuild): String = ???
+  def sbtSupertypes = Seq("SbtModule", "PublishModule") // always publish
 
-  override def extractIrBuild(
-      cfg: Config,
-      baseInfo: IrBaseInfo,
-      build: Node[IrBuild],
-      packages: Map[(String, String, String), String]
-  ): IrBuild = ???
-
-  /*
   def getBaseInfo(
-      input: Tree[Node[ProjectModel]],
+      input: (BuildInfo, Tree[Node[Project]]),
       cfg: Config,
       baseModule: String,
       packagesSize: Int
   ): IrBaseInfo = {
-    val project = {
-      val projects = input.nodes(Tree.Traversal.BreadthFirst).map(_.value).toSeq
-      cfg.baseProject
-        .flatMap(name => projects.collectFirst { case m if name == m.name => m })
-        .orElse(projects.collectFirst { case m if null != m.maven().pom() => m })
-        .orElse(projects.collectFirst { case m if !m.maven().repositories().isEmpty => m })
-        .getOrElse(input.node.value)
-    }
-    if (packagesSize > 1) {
-      println(s"settings from ${project.name()} will be shared in base module")
-    }
-    val supertypes =
-      Seq("MavenModule") ++
-        Option.when(null != project.maven().pom()) { "PublishModule" }
+    val buildInfo = input._1
 
-    val javacOptions = getJavacOptions(project)
-    val repos = getRepositories(project)
-    val pomSettings = extractPomSettings(project)
-    val publishVersion = getPublishVersion(project)
-    val publishProperties = getPublishProperties(project, cfg.shared)
+    val javacOptions = getJavacOptions(buildInfo)
+    val scalacOptions = buildInfo.scalacOptions
+    val repositories = getRepositories(buildInfo)
+    val pomSettings = extractPomSettings(buildInfo.buildPublicationInfo)
+    val publishVersion = getPublishVersion(buildInfo)
 
     val typedef = IrTrait(
-      cfg.shared.jvmId,
+      None, // There doesn't seem to be a Java version setting in sbt. See https://stackoverflow.com/a/76456295/5082913.
       baseModule,
-      supertypes,
+      sbtSupertypes,
       javacOptions,
+      scalacOptions,
       pomSettings,
       publishVersion,
-      publishProperties,
-      repos
+      null, // not available in sbt as it seems
+      repositories
     )
 
-    IrBaseInfo(javacOptions, repos, pomSettings == null, publishVersion, Seq.empty, typedef)
+    IrBaseInfo(
+      javacOptions,
+      scalacOptions,
+      repositories,
+      noPom = false, // always publish
+      publishVersion,
+      Seq.empty,
+      typedef
+    )
   }
 
   override def extractIrBuild(
       cfg: Config,
       baseInfo: IrBaseInfo,
-      build: Node[ProjectModel],
+      build: Node[Project],
       packages: Map[(String, String, String), String]
   ): IrBuild = {
     val project = build.value
-    val scopedDeps = extractScopedDeps(project, packages, cfg)
-    val version = getPublishVersion(project)
+    val buildInfo = project.buildInfo
+    val configurationDeps = extractConfigurationDeps(project, packages, cfg)
+    val version = getPublishVersion(buildInfo)
     IrBuild(
-      scopedDeps = scopedDeps,
+      scopedDeps = configurationDeps,
       testModule = cfg.shared.testModule,
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
-      repositories = getRepositories(project).diff(baseInfo.repositories),
-      javacOptions = getJavacOptions(project).diff(baseInfo.javacOptions),
-      projectName = getArtifactId(project),
-      pomSettings = if (baseInfo.noPom) extractPomSettings(project) else null,
+      repositories = getRepositories(buildInfo).diff(baseInfo.repositories),
+      javacOptions = getJavacOptions(buildInfo).diff(baseInfo.javacOptions),
+      scalacOptions = buildInfo.scalacOptions.map(scalacOptions =>
+        baseInfo.scalacOptions.fold(scalacOptions)(baseScalacOptions =>
+          scalacOptions.diff(baseScalacOptions)
+        )
+      ),
+      projectName = project.name,
+      pomSettings =
+        if (baseInfo.noPom) extractPomSettings(buildInfo.buildPublicationInfo) else null,
       publishVersion = if (version == baseInfo.publishVersion) null else version,
-      packaging = getPomPackaging(project),
-      // not available
-      pomParentArtifact = null,
-      // skipped, requires relatively new API (JavaPluginExtension.getSourceSets)
+      packaging = null, // not available in sbt as it seems
+      pomParentArtifact = null, // not available
       resources = Nil,
       testResources = Nil,
-      publishProperties = getPublishProperties(project, cfg.shared)
+      publishProperties = Nil // not available in sbt as it seems
     )
   }
 
   def getModuleSupertypes(cfg: Config): Seq[String] =
-    Seq(cfg.shared.baseModule.getOrElse("MavenModule"))
+    cfg.shared.baseModule.fold(sbtSupertypes)(Seq(_))
 
-  def getPackage(project: ProjectModel): (String, String, String) = {
-    (project.group(), project.name(), project.version())
+  def getPackage(project: Project): (String, String, String) = {
+    val buildPublicationInfo = project.buildInfo.buildPublicationInfo
+    (buildPublicationInfo.organization.orNull, project.name, buildPublicationInfo.version.orNull)
   }
 
-  def getArtifactId(model: ProjectModel): String = model.name()
+  def getArtifactId(project: Project): String = project.name
 
-  def getMillSourcePath(model: ProjectModel): Path = os.Path(model.directory())
+  def getMillSourcePath(project: Project): Path = os.Path(project.projectDirectory)
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] = {
+  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Project]): Seq[String] =
     Seq("RootModule") ++
-      Option.when(null != build.value.maven().pom() && baseInfo.noPom) { "PublishModule" } ++
       Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
         getModuleSupertypes(cfg)
-      }.toSeq.flatten
-  }
+      }.iterator.toSeq.flatten
 
-  def groupArtifactVersion(dep: JavaModel.Dep): (String, String, String) =
-    (dep.group(), dep.name(), dep.version())
+  def groupArtifactVersion(dep: Dependency): (String, String, String) =
+    (dep.organization, dep.name, dep.revision)
 
-  def getJavacOptions(project: ProjectModel): Seq[String] = {
-    val _java = project._java()
-    if (null == _java) Seq.empty
-    else _java.javacOptions().asScala.toSeq
-  }
+  def getJavacOptions(buildInfo: BuildInfo): Seq[String] =
+    buildInfo.javacOptions.getOrElse(Seq.empty)
 
-  def getRepositories(project: ProjectModel): Seq[String] =
-    project.maven().repositories().asScala.toSeq.sorted.map(uri =>
-      s"coursier.maven.MavenRepository(${escape(uri.toString)})"
+  def getRepositories(buildInfo: BuildInfo): Seq[String] =
+    buildInfo.resolvers.getOrElse(Seq.empty).map(resolver =>
+      s"coursier.maven.MavenRepository(${escape(resolver.root)})"
     )
 
-  def getPomPackaging(project: ProjectModel): String = {
-    val pom = project.maven().pom()
-    if (null == pom) null else pom.packaging()
-  }
-
-  def getPublishProperties(project: ProjectModel, cfg: BuildGenUtil.Config): Seq[(String, String)] =
-    if (cfg.publishProperties.value) {
-      val pom = project.maven().pom()
-      if (null == pom) Seq.empty
-      else pom.properties().iterator().asScala
-        .map(prop => (prop.key(), prop.value()))
-        .toSeq
-    } else Seq.empty
-
-  def getPublishVersion(project: ProjectModel): String =
-    project.version() match {
-      case "" | "unspecified" => null
-      case version => version
-    }
+  def getPublishVersion(buildInfo: BuildInfo): String =
+    buildInfo.buildPublicationInfo.version.orNull
 
-  def interpIvy(dep: JavaModel.Dep): String = {
-    BuildGenUtil.renderIvyString(dep.group(), dep.name(), dep.version())
+  // originally named `ivyInterp` in the Maven and module
+  def renderIvy(dependency: Dependency): String = {
+    // type, classifier, and exclusions are not processed yet
+    import dependency.*
+    s"ivy\"$organization:$name${if (crossVersion) "::" else ":"}$revision\""
   }
 
-  def extractPomSettings(project: ProjectModel): IrPom = {
-    val pom = project.maven.pom()
-    if (null == pom) null
-    else {
-      IrPom(
-        pom.description(),
-        project.group(), // Mill uses group for POM org
-        pom.url(),
-        licenses = pom.licenses().asScala
-          .map(lic => IrLicense(lic.name(), lic.name(), lic.url()))
-          .toSeq,
-        versionControl = Option(pom.scm()).fold(IrVersionControl(null, null, null, null))(scm =>
-          IrVersionControl(scm.url(), scm.connection(), scm.devConnection(), scm.tag())
-        ),
-        developers = pom.devs().asScala
-          .map(dev => IrDeveloper(dev.id(), dev.name(), dev.url(), dev.org(), dev.orgUrl()))
-          .toSeq
-      )
-    }
+  def extractPomSettings(buildPublicationInfo: BuildPublicationInfo): IrPom = {
+    import buildPublicationInfo.*
+    // always publish
+    /*
+    if (
+      Seq(
+        description,
+        homepage,
+        licenses,
+        organizationName,
+        organizationHomepage,
+        developers,
+        scmInfo
+      ).forall(_.isEmpty)
+    )
+      null
+    else
+     */
+    IrPom(
+      description.getOrElse(""),
+      organization.getOrElse(""),
+      organizationHomepage.fold("")(_.getOrElse("")),
+      licenses.getOrElse(Seq.empty).map(license => IrLicense(license._1, license._1, license._2)),
+      scmInfo.flatten.fold(IrVersionControl(null, null, null, null))(scmInfo => {
+        import scmInfo.*
+        IrVersionControl(browseUrl, connection, devConnection.orNull, null)
+      }),
+      developers.getOrElse(Seq.empty).map { developer =>
+        import developer.*
+        IrDeveloper(id, name, url, null, null)
+      }
+    )
   }
 
-  def extractScopedDeps(
-      project: ProjectModel,
+  def extractConfigurationDeps(
+      project: Project,
       packages: PartialFunction[(String, String, String), String],
       cfg: Config
   ): IrScopedDeps = {
-    var sd = IrScopedDeps()
-    val hasTest = os.exists(os.Path(project.directory()) / "src/test")
-    val _java = project._java()
-    if (null != _java) {
-      val ivyDep: JavaModel.Dep => String =
-        cfg.shared.depsObject.fold(interpIvy(_)) { objName => dep =>
-          val depName = s"`${dep.group()}:${dep.name()}`"
-          sd = sd.copy(namedIvyDeps = sd.namedIvyDeps :+ (depName, interpIvy(dep)))
-          s"$objName.$depName"
+    // refactored to a functional approach from the original imperative code in Maven and Gradle
+
+    val allDepsByConfiguration = project.allDependencies.groupBy(_.configurations match {
+      case None => Default
+      case Some(configuration) => configuration match {
+          case "compile" => Default
+          case "test" => Test
+          case "runtime" => Run
+          case "provided" | "optional" => Compile
         }
+    })
 
-      def appendIvyDepPackage(
-          deps: IterableOnce[JavaModel.Dep],
-          onPackage: String => IrScopedDeps,
-          onIvy: (String, (String, String, String)) => IrScopedDeps
-      ): Unit = {
-        for (dep <- deps.iterator) {
-          val id = groupArtifactVersion(dep)
-          if (packages.isDefinedAt(id)) sd = onPackage(packages(id))
-          else {
-            val ivy = ivyDep(dep)
-            sd = onIvy(ivy, id)
-          }
-        }
-      }
-      _java.configs().forEach { config =>
-        import JavaPlugin.*
-
-        val conf = config.name()
-        conf match {
-          case IMPLEMENTATION_CONFIGURATION_NAME | API_CONFIGURATION_NAME =>
-            appendIvyDepPackage(
-              config.deps.asScala,
-              onPackage = v => sd.copy(mainModuleDeps = sd.mainModuleDeps + v),
-              onIvy = (v, id) =>
-                if (isBom(id)) sd.copy(mainBomIvyDeps = sd.mainBomIvyDeps + v)
-                else sd.copy(mainIvyDeps = sd.mainIvyDeps + v)
-            )
-
-          case COMPILE_ONLY_CONFIGURATION_NAME | COMPILE_ONLY_API_CONFIGURATION_NAME =>
+    case class Deps[I, M](ivy: Seq[I], module: Seq[M])
 
-            appendIvyDepPackage(
-              config.deps.asScala,
-              onPackage = v => sd.copy(mainCompileModuleDeps = sd.mainCompileModuleDeps + v),
-              onIvy = (v, id) => sd.copy(mainCompileIvyDeps = sd.mainCompileIvyDeps + v)
-            )
-
-          case RUNTIME_ONLY_CONFIGURATION_NAME =>
-            appendIvyDepPackage(
-              config.deps.asScala,
-              onPackage = v => sd.copy(mainRunModuleDeps = sd.mainRunModuleDeps + v),
-              onIvy = (v, id) => sd.copy(mainRunIvyDeps = sd.mainRunIvyDeps + v)
-            )
-
-          case TEST_IMPLEMENTATION_CONFIGURATION_NAME =>
-
-            appendIvyDepPackage(
-              config.deps.asScala,
-              onPackage = v => sd.copy(testModuleDeps = sd.testModuleDeps + v),
-              onIvy = (v, id) =>
-                if (isBom(id)) sd.copy(testBomIvyDeps = sd.testBomIvyDeps + v)
-                else sd.copy(testIvyDeps = sd.testIvyDeps + v)
-            )
-            config.deps.forEach { dep =>
-              if (hasTest && sd.testModule.isEmpty) {
-                sd = sd.copy(testModule = testModulesByGroup.get(dep.group()))
-              }
-            }
-
-          case TEST_COMPILE_ONLY_CONFIGURATION_NAME =>
-            appendIvyDepPackage(
-              config.deps.asScala,
-              onPackage = v => sd.copy(testCompileModuleDeps = sd.testCompileModuleDeps + v),
-              onIvy = (v, id) => sd.copy(testCompileIvyDeps = sd.testCompileIvyDeps + v)
+    // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
+    val ivyAndModuleDepsByConfiguration: Map[IrDependencyType, Deps[Dependency, String]] =
+      allDepsByConfiguration.view.mapValues(deps => {
+        val tuple2 = deps.partitionMap(dep => {
+          val id = groupArtifactVersion(dep)
+          if (packages.isDefinedAt(id)) Right(packages(id))
+          else Left(dep)
+        })
+        Deps(tuple2._1, tuple2._2)
+      }).toMap
+
+    val testIvyAndModuleDeps = ivyAndModuleDepsByConfiguration.get(Test)
+    val testIvyDeps = testIvyAndModuleDeps.map(_.ivy)
+    val hasTest = os.exists(os.Path(project.projectDirectory) / "src/test")
+    val testModule = Option.when(hasTest)(
+      testIvyDeps.flatMap(_.collectFirst(Function.unlift(dep =>
+        testModulesByGroup.get(dep.organization)
+      )))
+    ).flatten
+
+    cfg.shared.depsObject.fold({
+      val default = ivyAndModuleDepsByConfiguration.get(Default)
+      val compile = ivyAndModuleDepsByConfiguration.get(Compile)
+      val run = ivyAndModuleDepsByConfiguration.get(Run)
+      val test = testIvyAndModuleDeps
+      IrScopedDeps(
+        Seq.empty,
+        SortedSet.empty,
+        // Using `fold` here causes issues with type inference.
+        SortedSet.from(default.map(_.ivy.iterator.map(renderIvy)).getOrElse(Iterator.empty)),
+        SortedSet.from(default.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.from(compile.map(_.ivy.iterator.map(renderIvy)).getOrElse(Iterator.empty)),
+        SortedSet.from(compile.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.from(run.map(_.ivy.iterator.map(renderIvy)).getOrElse(Iterator.empty)),
+        SortedSet.from(run.map(_.module).getOrElse(Seq.empty)),
+        testModule,
+        SortedSet.empty,
+        SortedSet.from(testIvyDeps.map(_.iterator.map(renderIvy)).getOrElse(Iterator.empty)),
+        SortedSet.from(test.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.empty,
+        SortedSet.empty
+      )
+    })(objectName => {
+      // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
+      val extractedIvyAndModuleDepsByConfiguration
+          : Map[IrDependencyType, Deps[((String, String), String), String]] =
+        ivyAndModuleDepsByConfiguration.view.mapValues({
+          case Deps(ivy, module) =>
+            Deps(
+              ivy.map(dep => {
+                val depName = s"`${dep.organization}:${dep.name}`"
+                ((depName, renderIvy(dep)), s"$objectName.$depName")
+              }),
+              module
             )
-
-          case name =>
-            config.deps.forEach { dep =>
-              val id = groupArtifactVersion(dep)
-              println(s"ignoring $name dependency $id")
-            }
-        }
-      }
-    }
-    sd
+        }).toMap
+
+      val default = extractedIvyAndModuleDepsByConfiguration.get(Default)
+      val compile = extractedIvyAndModuleDepsByConfiguration.get(Compile)
+      val run = extractedIvyAndModuleDepsByConfiguration.get(Run)
+      val test = extractedIvyAndModuleDepsByConfiguration.get(Test)
+      IrScopedDeps(
+        extractedIvyAndModuleDepsByConfiguration.values.flatMap(_.ivy.iterator.map(_._1)).toSeq,
+        SortedSet.empty,
+        SortedSet.from(default.map(_.ivy.iterator.map(_._2)).getOrElse(Iterator.empty)),
+        SortedSet.from(default.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.from(compile.map(_.ivy.iterator.map(_._2)).getOrElse(Iterator.empty)),
+        SortedSet.from(compile.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.from(run.map(_.ivy.iterator.map(_._2)).getOrElse(Iterator.empty)),
+        SortedSet.from(run.map(_.module).getOrElse(Seq.empty)),
+        testModule,
+        SortedSet.empty,
+        SortedSet.from(test.map(_.ivy.iterator.map(_._2)).getOrElse(Iterator.empty)),
+        SortedSet.from(test.map(_.module).getOrElse(Seq.empty)),
+        SortedSet.empty,
+        SortedSet.empty
+      )
+    })
   }
-   */
 
   @main
   @mill.api.internal
   case class Config(
-      shared: BuildGenUtil.Config
+      shared: BuildGenUtil.BasicConfig
   )
 }
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
new file mode 100644
index 00000000000..7cbc35ca8e5
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -0,0 +1,29 @@
+package build
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule with SbtModule with PublishModule {
+
+  def artifactName = "Scala Seed Project"
+
+  def ivyDeps = super.ivyDeps() ++
+    Agg(ivy"org.scala-lang:scala-library:2.13.12")
+
+  def pomSettings = PomSettings(
+    "Scala Seed Project",
+    "",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  object test extends MavenTests with TestModule.Munit {
+
+    def ivyDeps = super.ivyDeps() ++ Agg(ivy"org.scalameta:munit::0.7.29")
+
+  }
+}
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index ee5f9bcc7d0..5331e959f9d 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -12,7 +12,7 @@ object BuildGenTests extends TestSuite {
       val sourceRoot = os.sub / "scala-seed-project"
       val expectedRoot = os.sub / "expected/scala-seed-project"
       assert(
-        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
+        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot, true)
       )
     }
 

From 8b141aa11153c8987ba655244a57327d89d8c805 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sat, 15 Feb 2025 21:08:14 +0800
Subject: [PATCH 11/70] Remove the unnecessary code marked with TODOs to be
 removed in the previous commit, adjust the format of some code, and inline an
 sbt task

---
 .../sbt/models/src/mill/main/sbt/Models.scala | 172 +-------------
 .../mill/main/sbt/ExportBuildPlugin.scala     | 218 ++++--------------
 2 files changed, 48 insertions(+), 342 deletions(-)

diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 6c39a33bf5f..23b608d227e 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -7,32 +7,6 @@ import upickle.default.{macroRW, ReadWriter => RW}
 
 object Models {
   type URL = String
-
-  // TODO Remove. This seems not supported.
-
-  type Id[X] = X // not working with uPickle
-  /*object Id {
-    //implicit def rw[T](tRw : RW[T]) : RW[Id[T]] = tRw
-    implicit def rw[T: RW]: RW[Id[T]] = macroRW
-  }*/
-}
-
-// TODO Remove. Not used.
-/**
- * A wrapper added because [[Models.Id]] does not work with uPickle.
- * @param wrappedValue named this way in order not to conflict with [[sbt.std.MacroValue.value]]
- */
-case class Wrapper[+A](wrappedValue: A) extends AnyVal {
-  def map[B](f: A => B): Wrapper[B] = Wrapper(f(wrappedValue))
-}
-object Wrapper {
-  import scala.language.implicitConversions
-  implicit def to[A](value: A): Wrapper[A] =
-    Wrapper(value)
-  implicit def from[A](wrapper: Wrapper[A]): A =
-    wrapper.wrappedValue
-
-  implicit def rw[T: RW]: RW[Wrapper[T]] = macroRW
 }
 
 case class BuildExport(
@@ -44,136 +18,6 @@ object BuildExport {
   implicit val rw: RW[BuildExport] = macroRW
 }
 
-// TODO remove these plain ones
-
-case class PlainBuildInfo(
-    buildPublicationInfo: PlainBuildPublicationInfo,
-    /** @see [[Keys.javacOptions]] */
-    javacOptions: Seq[String],
-    /** @see [[Keys.resolvers]] */
-    resolvers: Seq[Resolver]
-)
-object PlainBuildInfo {
-  implicit val rw: RW[PlainBuildInfo] = macroRW
-}
-
-case class PlainBuildPublicationInfo(
-    /** @see [[Keys.description]] */
-    description: String,
-    /**
-     * corresponds to `url` in POM
-     *
-     * @see [[Keys.homepage]]
-     */
-    homepage: Option[String],
-    /** @see [[Keys.licenses]] */
-    licenses: Seq[License],
-    // organization: Option[String],
-    /*
-                                      /**
-     * corresponds to Maven's `organization` in POM
-     *
-     * @see [[Keys.organization]]
-     */
-                                      organizationName: String,
-     */
-    /**
-     * corresponds to `organizationUrl` in POM
-     *
-     * @see [[Keys.organizationHomepage]]
-     */
-    organizationHomepage: Option[String],
-    /** @see [[Keys.developers]] */
-    developers: Seq[Developer],
-    /** @see [[Keys.scmInfo]] */
-    scmInfo: Option[ScmInfo]
-)
-object PlainBuildPublicationInfo {
-  implicit val rw: RW[PlainBuildPublicationInfo] = macroRW
-
-  /** @see [[sbt.librarymanagement.License]] */
-  type License = (String, URL)
-}
-
-/*
-TODO I used higher-kinded types here along with some higher-rank types (`GetValueFn` and `MapFn`) in the sbt plugin,
- because I first thought that the default build info's members don't need to be wrapped with `Option` while the project build info's members do,
- and we can reuse some more code this way,
- but it turns out that both kinds have to be wrapped with `Option` and the abstraction doesn't work with the sbt `value` macros.
- Most likely we can just replace `F` with `Option` in them and remove the `TC` suffixes,
- resulting in `mill.main.sbt.BuildInfo` below,
- unless they can possibly provide more extensibility, which is unlikely as I think now.
- See other related definitions such as `Id`, `Wrapper`,
- `getBuildInfo[F[_]](ref: Reference, getValue: GetValueFn[F], map: MapFn[F]): BuildInfoTC[F]`, `GetValueFn`, and `MapFn`.
- */
-
-case class BuildInfoTC[F[_]](
-    buildPublicationInfo: BuildPublicationInfoTC[F],
-    /** @see [[Keys.javacOptions]] */
-    javacOptions: F[Seq[String]],
-    /** @see [[Keys.scalacOptions]] */
-    scalacOptions: F[Seq[String]],
-    /** @see [[Keys.resolvers]] */
-    resolvers: F[Seq[Resolver]]
-)
-object BuildInfoTC {
-  type BuildInfo = BuildInfoTC[Wrapper]
-  implicit val wrapperRw: RW[BuildInfo] = macroRW
-  type OptionBuildInfo = BuildInfoTC[Option]
-  implicit val optionRw: RW[OptionBuildInfo] = macroRW
-}
-
-case class BuildPublicationInfoTC[F[_]](
-    /** @see [[Keys.description]] */
-    description: F[String],
-    /**
-     * corresponds to `url` in POM
-     *
-     * @see [[Keys.homepage]]
-     */
-    homepage: F[Option[String]],
-    /** @see [[Keys.licenses]] */
-    licenses: F[Seq[PlainBuildPublicationInfo.License]],
-    // organization: Option[String],
-    /*
-    /**
-     * corresponds to Maven's `organization` in POM
-     *
-     * @see [[Keys.organization]]
-     */
-    organizationName: F[String],
-     */
-    /**
-     * corresponds to `organizationUrl` in POM
-     *
-     * @see [[Keys.organizationHomepage]]
-     */
-    organizationHomepage: F[Option[String]],
-    /** @see [[Keys.developers]] */
-    developers: F[Seq[Developer]],
-    /** @see [[Keys.scmInfo]] */
-    scmInfo: F[Option[ScmInfo]]
-)
-object BuildPublicationInfoTC {
-
-  /** @see [[sbt.librarymanagement.License]] */
-  type License = (String, URL)
-
-  /*
-  // This does not work: "could not find implicit value for parameter e: upickle.default.Reader[F[String]]".
-  implicit def rw[F[_]]: RW[BuildPublicationInfoTC[F]] = macroRW
-   */
-  /*
-  // This does not work: "could not find implicit value for parameter e: upickle.default.Reader[mill.main.sbt.Models.Id[Seq[mill.main.sbt.BuildPublicationInfo.License]]]".
-  type BuildPublicationInfo = BuildPublicationInfoTC[Id]
-  implicit val IdRw: RW[BuildPublicationInfo] = macroRW
-   */
-  type BuildPublicationInfo = BuildPublicationInfoTC[Wrapper]
-  implicit val wrapperRw: RW[BuildPublicationInfo] = macroRW
-  type OptionBuildPublicationInfo = BuildPublicationInfoTC[Option]
-  implicit val optionRw: RW[OptionBuildPublicationInfo] = macroRW
-}
-
 case class BuildInfo(
     buildPublicationInfo: BuildPublicationInfo,
     /** @see [[Keys.javacOptions]] */
@@ -200,7 +44,7 @@ case class BuildPublicationInfo(
      */
     homepage: Option[Option[String]],
     /** @see [[Keys.licenses]] */
-    licenses: Option[Seq[PlainBuildPublicationInfo.License]],
+    licenses: Option[Seq[License]],
     /**
      * corresponds to `groupId` in POM and Mill's `PomSettings.organization`
      *
@@ -273,24 +117,10 @@ case class Project(
     // dirs: ProjectDirs, // relative
     projectDirectory: String,
     buildInfo: BuildInfo,
-    // dependencyConfigurations: Seq[DependencyConfiguration] // TODO remove
     allDependencies: Seq[Dependency]
 )
 object Project {
   implicit val rw: RW[Project] = macroRW
-
-  // TODO Remove. Not used.
-  type ProjectDirs = Seq[String]
-}
-
-// TODO Remove. For an old implementation of retrieving `Configuration / allDependencies` that doesn't work.
-case class DependencyConfiguration(
-    id: String,
-    allDependencies: Seq[Dependency]
-    /*, projectDependencies: Seq[ProjectDirs], libraryDependencies: Seq[LibraryDependency]*/
-)
-object DependencyConfiguration {
-  implicit val rw: RW[DependencyConfiguration] = macroRW
 }
 
 case class Dependency(
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index 64c6e71d4c4..bff727ea561 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -1,7 +1,6 @@
 package mill.main.sbt
 
 import sbt.Keys.*
-import sbt.Project.extract
 import sbt.io.IO
 import sbt.librarymanagement.Disabled
 import sbt.{Def, Developer as _, Project as _, Resolver as _, ScmInfo as _, *}
@@ -18,55 +17,12 @@ object ExportBuildPlugin extends AutoPlugin {
     val millInitBuildInfo = taskKey[BuildInfo](
       "get the `mill.main.sbt.BuildInfo` model of this build or this project"
     )
-    // TODO Remove. No longer used.
-    val millInitDependencyConfiguration = taskKey[DependencyConfiguration](
-      "get the `mill.main.sbt.DependencyConfiguration` model of this project and configuration"
-    )
-    val millInitAllDependencies = taskKey[Seq[Dependency]](
-      "get the all the `mill.main.sbt.Dependency`s of this project"
-    )
+    // not used anymore
+    val millInitAllDependencies = taskKey[Seq[Dependency]]("get the all the `mill.main.sbt.Dependency`s of this project")
     val millInitProject = taskKey[Project]("get the `mill.main.sbt.Project` model of this project")
     val millInitExportBuild = taskKey[File]("export the build in a JSON file for `mill init`")
   }
 
-  // TODO `getBuildInfo` along with `MapFn` and `GetValueFn` does not work with the `value` macro. Remove.
-
-  trait MapFn[F[_]] {
-    // def apply[A, B](fa : F[A], f: A => B): F[B] // Type inference doesn't work well with this.
-    def apply[A, B](fa: F[A])(f: A => B): F[B]
-  }
-
-  trait GetValueFn[F[_]] {
-    def apply[T](key: SettingKey[T]): F[T]
-
-    def apply[T](key: TaskKey[T]): F[T]
-  }
-
-  def getBuildInfo[F[_]](ref: Reference, getValue: GetValueFn[F], map: MapFn[F]): BuildInfoTC[F] =
-    BuildInfoTC(
-      BuildPublicationInfoTC(
-        getValue(ref / description),
-        map(getValue(ref / homepage))(_.map(_.toExternalForm)),
-        map(getValue(ref / licenses))(_.map { case (name, url) => (name, url.toExternalForm) }),
-        //getValue(ref / organizationName), // not needed
-        map(getValue(ref / organizationHomepage))(_.map(_.toExternalForm)),
-        map(getValue(ref / developers))(_.map(developer =>
-          Developer(developer.id, developer.name, developer.email, developer.url.toExternalForm)
-        )),
-        map(getValue(ref / scmInfo))(_.map(scmInfo =>
-          ScmInfo(scmInfo.browseUrl.toExternalForm, scmInfo.connection, scmInfo.devConnection)
-        ))
-      ),
-      getValue(ref / javacOptions),
-      getValue(ref / scalacOptions),
-      map(getValue(ref / resolvers))(_.flatMap {
-        case mavenRepository: MavenRepository => Some(Resolver(mavenRepository.root))
-        case resolver =>
-          println(s"A `Resolver` which is not a `MavenRepository` is skipped: $resolver")
-          None
-      })
-    )
-
   import autoImport.*
 
   val buildInfoSetting = millInitBuildInfo := BuildInfo(
@@ -101,38 +57,41 @@ object ExportBuildPlugin extends AutoPlugin {
     buildInfoSetting
   )
 
-  // TODO Remove. For an old implementation that depends on retrieving `configuration / allDependencies` which doesn't work.
-  private val neededConfigurations = Seq(Compile, Test, Runtime, Default, Provided, Optional)
-
-  // TODO Remove. No longer used. Replaced by `millInitAllDependencies`.
-  val millInitDependencyConfigurationSetting =
-    millInitDependencyConfiguration := DependencyConfiguration(
-      configuration.value.id,
-
-      /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
-      /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
-        Dependency(
-          moduleID.organization,
-          moduleID.name,
-          moduleID.crossVersion match {
-            case Disabled => false
-            case _: Binary => true
-            case crossVersion =>
-              println(s"Unsupported `CrossVersion`: $crossVersion")
-              false
+  override lazy val projectSettings: Seq[Setting[?]] = Seq(
+    buildInfoSetting,
+    millInitProject :=
+      Project(
+        //organization.value,
+        name.value,
+        //version.value,
+        //baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
+        baseDirectory.value.getPath,
+        {
+          // keep the project `BuildInfo` members only when they are different
+          val defaultBi = (ThisBuild / millInitBuildInfo).value
+          val projectBi = millInitBuildInfo.value
+          import projectBi.*
+          BuildInfo({
+            val defaultBpi = defaultBi.buildPublicationInfo
+            import projectBi.buildPublicationInfo.*
+            BuildPublicationInfo(
+              if (description != defaultBpi.description) description else None,
+              if (homepage != defaultBpi.homepage) homepage else None,
+              if (licenses != defaultBpi.licenses) licenses else None,
+              if (organization != defaultBpi.organization) organization else None,
+              //if (organizationName != defaultBpi.organizationName) organizationName else None, // not needed
+              if (organizationHomepage != defaultBpi.organizationHomepage) organizationHomepage else None,
+              if (developers != defaultBpi.developers) developers else None,
+              if (scmInfo != defaultBpi.scmInfo) scmInfo else None,
+              if (version != defaultBpi.version) version else None
+            )
           },
-          moduleID.revision,
-          moduleID.configurations
-        )
-      }
-    )
+            if (javacOptions != defaultBi.javacOptions) javacOptions else None,
+            if (scalacOptions != defaultBi.scalacOptions) scalacOptions else None,
+            if (resolvers != defaultBi.resolvers) resolvers else None
+          )
+        },
 
-  override lazy val projectSettings: Seq[Setting[?]] = Seq(
-    Seq(buildInfoSetting),
-    // TODO Remove. For an old implementation that depends on `configuration / allDependencies` which doesn't work.
-    neededConfigurations.flatMap(configuration => inConfig(configuration)(Seq(millInitDependencyConfigurationSetting))),
-    Seq(
-      millInitAllDependencies := {
         /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
         /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
           Dependency(
@@ -149,99 +108,16 @@ object ExportBuildPlugin extends AutoPlugin {
             moduleID.configurations
           )
         }
-      },
-      millInitProject := {
-        // TODO remove
-        val extracted = extract(state.value) // TODO move to a separate task if used
-        Project(
-          //organization.value,
-          name.value,
-          //version.value,
-          //baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
-          baseDirectory.value.getPath,
-          // TODO remove old implementation
-          /*
-          getBuildInfo[Option](
-            ThisProject,
-            new GetValueFn[Option] {
-              override def apply[T](key: SettingKey[T]): Option[T] = extracted.getOpt(key)
-
-              override def apply[T](key: TaskKey[T]): Option[T] =
-                ??? // extracted.getOpt(key).map(_.value)
-            },
-            new MapFn[Option] {
-              override def apply[A, B](fa: Option[A])(f: A => B): Option[B] = fa.map(f)
-            }
-          )
-           */
-          {
-            // keep the project `BuildInfo` members only when they are different
-            val defaultBi = (ThisBuild / millInitBuildInfo).value
-            val projectBi = millInitBuildInfo.value
-            import projectBi.*
-            BuildInfo({
-              val defaultBpi = defaultBi.buildPublicationInfo
-              import projectBi.buildPublicationInfo.*
-              BuildPublicationInfo(
-                if (description != defaultBpi.description) description else None,
-                if (homepage != defaultBpi.homepage) homepage else None,
-                if (licenses != defaultBpi.licenses) licenses else None,
-                if (organization != defaultBpi.organization) organization else None,
-                //if (organizationName != defaultBpi.organizationName) organizationName else None, // not needed
-                if (organizationHomepage != defaultBpi.organizationHomepage) organizationHomepage else None,
-                if (developers != defaultBpi.developers) developers else None,
-                if (scmInfo != defaultBpi.scmInfo) scmInfo else None,
-                if (version != defaultBpi.version) version else None
-              )
-            },
-              if (javacOptions != defaultBi.javacOptions) javacOptions else None,
-              if (scalacOptions != defaultBi.scalacOptions) scalacOptions else None,
-              if (resolvers != defaultBi.resolvers) resolvers else None
-            )
-          },
-          {
-            // TODO Remove. For an old implementation that depends on retrieving `configuration / allDependencies` which doesn't work.
-            millInitDependencyConfiguration.all(
-              ScopeFilter(configurations = inConfigurations(neededConfigurations *))
-            ).value
-            millInitAllDependencies.value
-          }
-        )
-      },
-      // `target.value` doesn't work in `globalSettings` and `buildSettings`, so this is added to `projectSettings.
-      millInitExportBuild := {
-        // TODO This does not work with the `value` macro. Remove.
-        /*
-        val defaultBuildInfo = getBuildInfo[Wrapper](
-          ThisBuild,
-          new GetValueFn[Wrapper] {
-            override def apply[T](key: SettingKey[T]): Wrapper[T] =
-              ??? // Wrapper(key.value) // Could not find proxy
-            override def apply[T](key: TaskKey[T]): Wrapper[T] =
-              ??? // Wrapper(key.value) // Could not find proxy
-          },
-          new MapFn[Wrapper] {
-            override def apply[A, B](fa: Wrapper[A])(f: A => B): Wrapper[B] = fa.map(f)
-          }
-        )
-         */
-
-        val defaultBuildInfo = (ThisBuild / millInitBuildInfo).value
-
-        // TODO remove the old implementation code
-        // `(projectRef / ...)` can't be used directly here due to macro limitations: "java.lang.IllegalArgumentException: Could not find proxy for projectRef: sbt.ProjectRef in ..."
-        /*
-        val allProjectPairs = buildStructure.value.allProjectPairs
-        val projects = allProjectPairs.map { case (resolvedProject, projectRef) => ??? }
-         */
-
-        val projects = millInitProject.all(ScopeFilter(inAnyProject)).value
-
-        val buildExport = BuildExport(defaultBuildInfo, projects)
-
-        val outputFile = target.value / "mill-init-build-export.json"
-        IO.write(outputFile, write(buildExport))
-        outputFile
-      }
-    )).flatten
+      ),
+    // `target.value` doesn't work in `globalSettings` and `buildSettings`, so this is added to `projectSettings.
+    millInitExportBuild := {
+      val defaultBuildInfo = (ThisBuild / millInitBuildInfo).value
+      val projects = millInitProject.all(ScopeFilter(inAnyProject)).value
+      val buildExport = BuildExport(defaultBuildInfo, projects)
+
+      val outputFile = target.value / "mill-init-build-export.json"
+      IO.write(outputFile, write(buildExport))
+      outputFile
+    }
+  )
 }

From 1fd0b652cffe8d14d2eebc9b652624495be5550a Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 15:41:32 +0800
Subject: [PATCH 12/70] Do not diff a subproject's `BuildInfo` with
 `ThisBuild`'s anymore in `ExportBuildPlugin` because its members are always
 needed when there is no `baseModule`

* Add a `takeIrPomIfNeeded` function to also set a module's `PomSettings` when it's different from a base module's `PomSettings`.
* Regenerate and update "test/resources/expected/scala-seed-project/build.mill".
---
 main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala | 3 +++
 .../src/main/scala/mill/main/sbt/ExportBuildPlugin.scala     | 5 +++--
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala        | 3 +--
 .../test/resources/expected/scala-seed-project/build.mill    | 4 +++-
 4 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index 9a879a590e4..cb140f386e3 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -47,6 +47,9 @@ object BuildGenUtil {
 
   }
 
+  def takeIrPomIfNeeded(baseInfo: IrBaseInfo, irPom: IrPom): IrPom =
+    if (baseInfo.noPom || irPom != baseInfo.moduleTypedef.pomSettings) irPom else null
+
   def renderIrPom(value: IrPom): String = {
     if (value == null) ""
     else {
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index bff727ea561..04f70b17633 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -66,7 +66,7 @@ object ExportBuildPlugin extends AutoPlugin {
         //version.value,
         //baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
         baseDirectory.value.getPath,
-        {
+        /*{
           // keep the project `BuildInfo` members only when they are different
           val defaultBi = (ThisBuild / millInitBuildInfo).value
           val projectBi = millInitBuildInfo.value
@@ -90,7 +90,8 @@ object ExportBuildPlugin extends AutoPlugin {
             if (scalacOptions != defaultBi.scalacOptions) scalacOptions else None,
             if (resolvers != defaultBi.resolvers) resolvers else None
           )
-        },
+        }*/
+        millInitBuildInfo.value,
 
         /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
         /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 4977a3168d0..5c6390c9860 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -197,8 +197,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
         )
       ),
       projectName = project.name,
-      pomSettings =
-        if (baseInfo.noPom) extractPomSettings(buildInfo.buildPublicationInfo) else null,
+      pomSettings = takeIrPomIfNeeded(baseInfo, extractPomSettings(buildInfo.buildPublicationInfo)),
       publishVersion = if (version == baseInfo.publishVersion) null else version,
       packaging = null, // not available in sbt as it seems
       pomParentArtifact = null, // not available
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index 7cbc35ca8e5..c992176f2b5 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -14,13 +14,15 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def pomSettings = PomSettings(
     "Scala Seed Project",
-    "",
+    "com.example",
     "",
     Seq(),
     VersionControl(None, None, None, None),
     Seq()
   )
 
+  def publishVersion = "0.1.0-SNAPSHOT"
+
   object test extends MavenTests with TestModule.Munit {
 
     def ivyDeps = super.ivyDeps() ++ Agg(ivy"org.scalameta:munit::0.7.29")

From f38991b2dff60f8f2741f3abc5b403e6f771aa5f Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 15:53:35 +0800
Subject: [PATCH 13/70] Move the "mill.scalalib.SbtModule" import into
 `SbtBuildGenMain` to fix the tests `./mill main.init.maven.test` and `./mill
 main.init.gradle.test` which were broken

---
 .../buildgen/src/mill/main/buildgen/BuildGenBase.scala     | 4 +++-
 .../buildgen/src/mill/main/buildgen/BuildGenUtil.scala     | 7 ++++---
 .../gradle/src/mill/main/gradle/GradleBuildGenMain.scala   | 2 ++
 .../init/maven/src/mill/main/maven/MavenBuildGenMain.scala | 2 ++
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala      | 2 ++
 5 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 261e5d58615..964d1f712fd 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -35,7 +35,7 @@ trait BuildGenBase[M, D, I] {
       val isNested = build.dirs.nonEmpty
       build.copy(value =
         BuildObject(
-          imports = BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size),
+          imports = BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size, extraImports),
           companions =
             shared.depsObject.fold(SortedMap.empty[String, BuildObject.Constants])(name =>
               SortedMap((name, SortedMap(inner.scopedDeps.namedIvyDeps.toSeq *)))
@@ -50,6 +50,8 @@ trait BuildGenBase[M, D, I] {
     }
   }
 
+  def extraImports: Seq[String]
+
   def getSuperTypes(cfg: C, baseInfo: IrBaseInfo, build: Node[M]): Seq[String]
 
   def getBaseInfo(
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index cb140f386e3..0a84560c2e0 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -132,14 +132,15 @@ object BuildGenUtil {
   def renderImports(
       baseModule: Option[String],
       isNested: Boolean,
-      packagesSize: Int
+      packagesSize: Int,
+      extraImports: Seq[String]
   ): SortedSet[String] = {
     scala.collection.immutable.SortedSet(
       "mill._",
       "mill.javalib._",
-      "mill.javalib.publish._",
-      "mill.scalalib.SbtModule"
+      "mill.javalib.publish._"
     ) ++
+      extraImports ++
       (if (isNested) baseModule.map(name => s"$$file.$name")
        else if (packagesSize > 1) Seq("$packages._")
        else None)
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index 2cfdb7fdeaf..e6bf7b9dd33 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -183,6 +183,8 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
     )
   }
 
+  override def extraImports: Seq[String] = Seq.empty
+
   def getModuleSupertypes(cfg: Config): Seq[String] =
     Seq(cfg.shared.basicConfig.baseModule.getOrElse("MavenModule"))
 
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index 7edc0add46a..abfe12ae98f 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -128,6 +128,8 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
     )
   }
 
+  override def extraImports: Seq[String] = Seq.empty
+
   def getModuleSupertypes(cfg: Config): Seq[String] = Seq("PublishModule", "MavenModule")
 
   def getPackage(model: Model): (String, String, String) = {
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 5c6390c9860..b610866f252 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -207,6 +207,8 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     )
   }
 
+  override def extraImports: Seq[String] = Seq("mill.scalalib.SbtModule")
+
   def getModuleSupertypes(cfg: Config): Seq[String] =
     cfg.shared.baseModule.fold(sbtSupertypes)(Seq(_))
 

From f70e81805c267c53f48c8afabfde2af4438b8c26 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 16:31:13 +0800
Subject: [PATCH 14/70] Export and import sbt's `scalaVersion` too

---
 .../buildgen/src/mill/main/buildgen/BuildGenUtil.scala    | 7 +++++++
 main/init/buildgen/src/mill/main/buildgen/ir.scala        | 3 +++
 main/init/sbt/models/src/mill/main/sbt/Models.scala       | 2 ++
 .../src/main/scala/mill/main/sbt/ExportBuildPlugin.scala  | 1 +
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala     | 8 ++++++--
 .../test/resources/expected/scala-seed-project/build.mill | 2 ++
 6 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index 0a84560c2e0..8ad38581ad2 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -32,6 +32,8 @@ object BuildGenUtil {
        |
        |${renderJavacOptions(javacOptions)}
        |
+       |${renderScalaVersion(scalaVersion)}
+       |
        |${renderScalacOptions(scalacOptions)}
        |
        |${renderPomSettings(renderIrPom(pomSettings))}
@@ -88,6 +90,8 @@ object BuildGenUtil {
        |
        |${renderJavacOptions(javacOptions)}
        |
+       |${renderScalaVersion(scalaVersion)}
+       |
        |${renderScalacOptions(scalacOptions)}
        |
        |${renderRepositories(repositories)}
@@ -392,6 +396,9 @@ object BuildGenUtil {
       args.iterator.map(escape)
     )
 
+  def renderScalaVersion(scalaVersion: Option[String]): String =
+    scalaVersion.fold("")(scalaVersion => s"def scalaVersion = ${escape(scalaVersion)}")
+
   def renderScalacOptions(args: Option[IterableOnce[String]]): String =
     args.fold("")(args =>
       optional(
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index d835498b66c..c41c272ec5b 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -41,6 +41,7 @@ case class IrTrait(
     baseModule: String,
     moduleSupertypes: Seq[String],
     javacOptions: Seq[String],
+    scalaVersion: Option[String],
     scalacOptions: Option[Seq[String]],
     pomSettings: IrPom,
     publishVersion: String,
@@ -84,6 +85,7 @@ case class IrBuild(
     dirs: Seq[String],
     repositories: Seq[String],
     javacOptions: Seq[String],
+    scalaVersion : Option[String],
     scalacOptions: Option[Seq[String]],
     projectName: String,
     pomSettings: IrPom,
@@ -115,6 +117,7 @@ case class IrScopedDeps(
 
 case class IrBaseInfo(
     javacOptions: Seq[String] = Nil,
+    scalaVersion : Option[String] = None,
     scalacOptions : Option[Seq[String]] = None,
     repositories: Seq[String] = Nil,
     noPom: Boolean = true,
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 23b608d227e..ae6a982ebac 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -22,6 +22,8 @@ case class BuildInfo(
     buildPublicationInfo: BuildPublicationInfo,
     /** @see [[Keys.javacOptions]] */
     javacOptions: Option[Seq[String]],
+    /** @see [[Keys.scalaVersion]] */
+    scalaVersion: Option[String],
     /** @see [[Keys.scalacOptions]] */
     scalacOptions: Option[Seq[String]],
     /** @see [[Keys.resolvers]] */
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index 04f70b17633..f80705477e1 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -44,6 +44,7 @@ object ExportBuildPlugin extends AutoPlugin {
       version.?.value
     ),
     javacOptions.?.value,
+    scalaVersion.?.value,
     scalacOptions.?.value,
     resolvers.?.value.map(_.flatMap {
       case mavenRepository: MavenRepository => Some(Resolver(mavenRepository.root))
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index b610866f252..277e9edc176 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -145,10 +145,10 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
   ): IrBaseInfo = {
     val buildInfo = input._1
 
+    import buildInfo.*
     val javacOptions = getJavacOptions(buildInfo)
-    val scalacOptions = buildInfo.scalacOptions
     val repositories = getRepositories(buildInfo)
-    val pomSettings = extractPomSettings(buildInfo.buildPublicationInfo)
+    val pomSettings = extractPomSettings(buildPublicationInfo)
     val publishVersion = getPublishVersion(buildInfo)
 
     val typedef = IrTrait(
@@ -156,6 +156,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       baseModule,
       sbtSupertypes,
       javacOptions,
+      scalaVersion,
       scalacOptions,
       pomSettings,
       publishVersion,
@@ -165,6 +166,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     IrBaseInfo(
       javacOptions,
+      scalaVersion,
       scalacOptions,
       repositories,
       noPom = false, // always publish
@@ -191,6 +193,8 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       dirs = build.dirs,
       repositories = getRepositories(buildInfo).diff(baseInfo.repositories),
       javacOptions = getJavacOptions(buildInfo).diff(baseInfo.javacOptions),
+      scalaVersion =
+        if (buildInfo.scalaVersion != baseInfo.scalaVersion) buildInfo.scalaVersion else null,
       scalacOptions = buildInfo.scalacOptions.map(scalacOptions =>
         baseInfo.scalacOptions.fold(scalacOptions)(baseScalacOptions =>
           scalacOptions.diff(baseScalacOptions)
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index c992176f2b5..de2f48bf26e 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -9,6 +9,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def artifactName = "Scala Seed Project"
 
+  def scalaVersion = "2.13.12"
+
   def ivyDeps = super.ivyDeps() ++
     Agg(ivy"org.scala-lang:scala-library:2.13.12")
 

From 7e1e2b6b8e23b18cc8fce3a51f5d79dde27bd1c3 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 16:52:53 +0800
Subject: [PATCH 15/70] Exclude the Scala Standard Libraries

---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 25 ++++++++++++-------
 .../expected/scala-seed-project/build.mill    |  3 ---
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 277e9edc176..5e42570af98 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -286,6 +286,10 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     )
   }
 
+  private def isScalaStandardLibrary(dep: Dependency) =
+    Seq("ch.epfl.lamp", "org.scala-lang").contains(dep.organization) &&
+      Seq("scala-library", "dotty-library", "scala3-library").contains(dep.name)
+
   def extractConfigurationDeps(
       project: Project,
       packages: PartialFunction[(String, String, String), String],
@@ -293,15 +297,18 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
   ): IrScopedDeps = {
     // refactored to a functional approach from the original imperative code in Maven and Gradle
 
-    val allDepsByConfiguration = project.allDependencies.groupBy(_.configurations match {
-      case None => Default
-      case Some(configuration) => configuration match {
-          case "compile" => Default
-          case "test" => Test
-          case "runtime" => Run
-          case "provided" | "optional" => Compile
-        }
-    })
+    val allDepsByConfiguration = project.allDependencies
+      // .view // This makes the types hard to deal with here thus commented out.
+      .filterNot(isScalaStandardLibrary)
+      .groupBy(_.configurations match {
+        case None => Default
+        case Some(configuration) => configuration match {
+            case "compile" => Default
+            case "test" => Test
+            case "runtime" => Run
+            case "provided" | "optional" => Compile
+          }
+      })
 
     case class Deps[I, M](ivy: Seq[I], module: Seq[M])
 
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index de2f48bf26e..27e391369ee 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -11,9 +11,6 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def scalaVersion = "2.13.12"
 
-  def ivyDeps = super.ivyDeps() ++
-    Agg(ivy"org.scala-lang:scala-library:2.13.12")
-
   def pomSettings = PomSettings(
     "Scala Seed Project",
     "com.example",

From 6f4c45dd336ec30827a33361b71555a5777b2322 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 17:23:30 +0800
Subject: [PATCH 16/70] Add the
 https://github.com/pbassiner/sbt-multi-project-example project to the test
 resources

Both `./mill main.init.sbt.test` and running `sbt` in the project directory fail with:

```
java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release
```

This is likely because I am using JDK 21.
---
 .../sbt-multi-project-example/LICENSE         |  21 +++
 .../sbt-multi-project-example/README.md       |  23 +++
 .../sbt-multi-project-example/build.sbt       | 139 ++++++++++++++++++
 .../common/src/main/scala/Model.scala         |   2 +
 .../common/src/test/scala/Test.scala          |   6 +
 .../multi1/src/main/scala/Main.scala          |  11 ++
 .../multi1/src/test/scala/Test.scala          |  13 ++
 .../multi2/src/main/scala/Main.scala          |  11 ++
 .../multi2/src/test/scala/Test.scala          |  14 ++
 .../project/build.properties                  |   1 +
 .../project/plugins.sbt                       |  12 ++
 .../src/mill/main/sbt/BuildGenTests.scala     |  11 +-
 12 files changed, 259 insertions(+), 5 deletions(-)
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/LICENSE
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/README.md
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/common/src/main/scala/Model.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/common/src/test/scala/Test.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/main/scala/Main.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/test/scala/Test.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/main/scala/Main.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/test/scala/Test.scala
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
 create mode 100644 main/init/sbt/test/resources/sbt-multi-project-example/project/plugins.sbt

diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/LICENSE b/main/init/sbt/test/resources/sbt-multi-project-example/LICENSE
new file mode 100644
index 00000000000..b54a8a16e99
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2017-2018 Pol Bassiner
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/README.md b/main/init/sbt/test/resources/sbt-multi-project-example/README.md
new file mode 100644
index 00000000000..3c7a82b0293
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/README.md
@@ -0,0 +1,23 @@
+# sbt-multi-project-example
+
+The goal of this example is to provide a multi-project build using `sbt` providing:
+* A single `build.sbt` file which allows for centralized configuration, dependency and build management
+* Each sub-project contains only its source code
+* Sub-projects can depend on other sub-projects
+* Only *deliverable* sub-projects produce a *fat-jar* using [sbt-assembly](https://github.com/sbt/sbt-assembly)
+
+# Example structure
+* sbt-multi-project-example/
+    * common/
+        * src/
+        * test/
+    * multi1/
+        * src/
+        * test/
+    * multi2/
+        * src/
+        * test/
+    * project/
+        * build.properties
+        * plugins.sbt
+    * build.sbt
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
new file mode 100644
index 00000000000..667fcaa1a66
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -0,0 +1,139 @@
+name := "sbt-multi-project-example"
+organization in ThisBuild := "com.pbassiner"
+scalaVersion in ThisBuild := "2.12.3"
+
+// PROJECTS
+
+lazy val global = project
+  .in(file("."))
+  .settings(settings)
+  .disablePlugins(AssemblyPlugin)
+  .aggregate(
+    common,
+    multi1,
+    multi2
+  )
+
+lazy val common = project
+  .settings(
+    name := "common",
+    settings,
+    libraryDependencies ++= commonDependencies
+  )
+  .disablePlugins(AssemblyPlugin)
+
+lazy val multi1 = project
+  .settings(
+    name := "multi1",
+    settings,
+    assemblySettings,
+    libraryDependencies ++= commonDependencies ++ Seq(
+      dependencies.monocleCore,
+      dependencies.monocleMacro
+    )
+  )
+  .dependsOn(
+    common
+  )
+
+lazy val multi2 = project
+  .settings(
+    name := "multi2",
+    settings,
+    assemblySettings,
+    libraryDependencies ++= commonDependencies ++ Seq(
+      dependencies.pureconfig
+    )
+  )
+  .dependsOn(
+    common
+  )
+
+// DEPENDENCIES
+
+lazy val dependencies =
+  new {
+    val logbackV        = "1.2.3"
+    val logstashV       = "4.11"
+    val scalaLoggingV   = "3.7.2"
+    val slf4jV          = "1.7.25"
+    val typesafeConfigV = "1.3.1"
+    val pureconfigV     = "0.8.0"
+    val monocleV        = "1.4.0"
+    val akkaV           = "2.5.6"
+    val scalatestV      = "3.0.4"
+    val scalacheckV     = "1.13.5"
+
+    val logback        = "ch.qos.logback"             % "logback-classic"          % logbackV
+    val logstash       = "net.logstash.logback"       % "logstash-logback-encoder" % logstashV
+    val scalaLogging   = "com.typesafe.scala-logging" %% "scala-logging"           % scalaLoggingV
+    val slf4j          = "org.slf4j"                  % "jcl-over-slf4j"           % slf4jV
+    val typesafeConfig = "com.typesafe"               % "config"                   % typesafeConfigV
+    val akka           = "com.typesafe.akka"          %% "akka-stream"             % akkaV
+    val monocleCore    = "com.github.julien-truffaut" %% "monocle-core"            % monocleV
+    val monocleMacro   = "com.github.julien-truffaut" %% "monocle-macro"           % monocleV
+    val pureconfig     = "com.github.pureconfig"      %% "pureconfig"              % pureconfigV
+    val scalatest      = "org.scalatest"              %% "scalatest"               % scalatestV
+    val scalacheck     = "org.scalacheck"             %% "scalacheck"              % scalacheckV
+  }
+
+lazy val commonDependencies = Seq(
+  dependencies.logback,
+  dependencies.logstash,
+  dependencies.scalaLogging,
+  dependencies.slf4j,
+  dependencies.typesafeConfig,
+  dependencies.akka,
+  dependencies.scalatest  % "test",
+  dependencies.scalacheck % "test"
+)
+
+// SETTINGS
+
+lazy val settings =
+commonSettings ++
+wartremoverSettings ++
+scalafmtSettings
+
+lazy val compilerOptions = Seq(
+  "-unchecked",
+  "-feature",
+  "-language:existentials",
+  "-language:higherKinds",
+  "-language:implicitConversions",
+  "-language:postfixOps",
+  "-deprecation",
+  "-encoding",
+  "utf8"
+)
+
+lazy val commonSettings = Seq(
+  scalacOptions ++= compilerOptions,
+  resolvers ++= Seq(
+    "Local Maven Repository" at "file://" + Path.userHome.absolutePath + "/.m2/repository",
+    Resolver.sonatypeRepo("releases"),
+    Resolver.sonatypeRepo("snapshots")
+  )
+)
+
+lazy val wartremoverSettings = Seq(
+  wartremoverWarnings in (Compile, compile) ++= Warts.allBut(Wart.Throw)
+)
+
+lazy val scalafmtSettings =
+  Seq(
+    scalafmtOnCompile := true,
+    scalafmtTestOnCompile := true,
+    scalafmtVersion := "1.2.0"
+  )
+
+lazy val assemblySettings = Seq(
+  assemblyJarName in assembly := name.value + ".jar",
+  assemblyMergeStrategy in assembly := {
+    case PathList("META-INF", xs @ _*) => MergeStrategy.discard
+    case "application.conf"            => MergeStrategy.concat
+    case x =>
+      val oldStrategy = (assemblyMergeStrategy in assembly).value
+      oldStrategy(x)
+  }
+)
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/common/src/main/scala/Model.scala b/main/init/sbt/test/resources/sbt-multi-project-example/common/src/main/scala/Model.scala
new file mode 100644
index 00000000000..4a64c26b8cc
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/common/src/main/scala/Model.scala
@@ -0,0 +1,2 @@
+final case class Entity(id: String, nested: NestedEntity)
+final case class NestedEntity(value: String)
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/common/src/test/scala/Test.scala b/main/init/sbt/test/resources/sbt-multi-project-example/common/src/test/scala/Test.scala
new file mode 100644
index 00000000000..81dc49be006
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/common/src/test/scala/Test.scala
@@ -0,0 +1,6 @@
+import org.scalatest.FunSuite
+
+class Test extends FunSuite {
+
+  test("common") {}
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/main/scala/Main.scala b/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/main/scala/Main.scala
new file mode 100644
index 00000000000..0ef089fe5f1
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/main/scala/Main.scala
@@ -0,0 +1,11 @@
+import monocle.macros.GenLens
+
+object Main extends App {
+  println("multi1 can use common sub-project")
+
+  val entity = Entity("id", NestedEntity("value"))
+
+  println("multi1 can use monocle dependency")
+
+  val idLens = GenLens[Entity](_.id)
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/test/scala/Test.scala b/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/test/scala/Test.scala
new file mode 100644
index 00000000000..f8eb44cc353
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/multi1/src/test/scala/Test.scala
@@ -0,0 +1,13 @@
+import monocle.macros.GenLens
+import org.scalatest.FunSuite
+
+class Test extends FunSuite {
+
+  test("multi1 can use common sub-project") {
+    val entity = Entity("id", NestedEntity("value"))
+  }
+
+  test("multi1 can use monocle dependency ") {
+    val idLens = GenLens[Entity](_.id)
+  }
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/main/scala/Main.scala b/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/main/scala/Main.scala
new file mode 100644
index 00000000000..9af1d57f7fb
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/main/scala/Main.scala
@@ -0,0 +1,11 @@
+object Main extends App {
+  println("multi2 can use common sub-project")
+
+  val entity = Entity("id", NestedEntity("value"))
+
+  println("multi2 can use pureconfig dependency")
+
+  import pureconfig._
+
+  implicit def hint[T]: ProductHint[T] = ProductHint[T](ConfigFieldMapping(CamelCase, KebabCase))
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/test/scala/Test.scala b/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/test/scala/Test.scala
new file mode 100644
index 00000000000..b5781c76add
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/multi2/src/test/scala/Test.scala
@@ -0,0 +1,14 @@
+import org.scalatest.FunSuite
+
+class Test extends FunSuite {
+
+  test("multi2 can use common sub-project") {
+    val entity = Entity("id", NestedEntity("value"))
+  }
+
+  test("multi2 can use pureconfig dependency") {
+    import pureconfig._
+
+    implicit def hint[T]: ProductHint[T] = ProductHint[T](ConfigFieldMapping(CamelCase, KebabCase))
+  }
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties b/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
new file mode 100644
index 00000000000..017bb86a23d
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
@@ -0,0 +1 @@
+sbt.version = 1.0.2
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/project/plugins.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/project/plugins.sbt
new file mode 100644
index 00000000000..7c3cee85fd4
--- /dev/null
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/project/plugins.sbt
@@ -0,0 +1,12 @@
+logLevel := Level.Warn
+
+addSbtPlugin("io.get-coursier" % "sbt-coursier" % "1.0.2")
+
+addSbtPlugin("com.timushev.sbt" % "sbt-updates" % "0.3.2")
+
+addSbtPlugin("org.scalastyle" %% "scalastyle-sbt-plugin" % "1.0.0")
+addSbtPlugin("org.wartremover" % "sbt-wartremover" % "2.2.1")
+
+addSbtPlugin("com.lucidchart" % "sbt-scalafmt-coursier" % "1.12")
+
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.5")
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index 5331e959f9d..48e92fb127e 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -16,15 +16,16 @@ object BuildGenTests extends TestSuite {
       )
     }
 
-    /*
-    test("application-library") {
-      val sourceRoot = os.sub / "application-library"
-      val expectedRoot = os.sub / "expected/application-library"
+    // from https://github.com/pbassiner/sbt-multi-project-example/tree/master
+    test("sbt-multi-project-example") {
+      val sourceRoot = os.sub / "sbt-multi-project-example"
+      val expectedRoot = os.sub / "expected/sbt-multi-project-example"
       assert(
-        checker.check(GradleBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
+        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot, true)
       )
     }
 
+    /*
     test("config") {
       val sourceRoot = os.sub / "application-library"
       val expectedRoot = os.sub / "expected/config"

From 913ef1d731ed98d08ecd46c93269f36574e9a20f Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 21:42:46 +0800
Subject: [PATCH 17/70] Generate the expected snapshots for
 "sbt-multi-project-example" and improve

1. Bump the sbt version in "sbt-multi-project-example" to v1.10.7
1. Print an info message to remind the user when the sbt command to run the `millInitExportBuild` sbt task fails.
1. Drop dependencies of unknown configurations.
1. Generate the expected snapshots for "sbt-multi-project-example" and review.
   1. Comment the Local Maven Repository as it's machine-dependent.
---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 37 +++++++---
 .../sbt-multi-project-example/build.mill      | 49 ++++++++++++++
 .../common/package.mill                       | 63 +++++++++++++++++
 .../multi1/package.mill                       | 67 +++++++++++++++++++
 .../multi2/package.mill                       | 66 ++++++++++++++++++
 .../sbt-multi-project-example/build.sbt       |  3 +-
 .../project/build.properties                  |  2 +-
 7 files changed, 274 insertions(+), 13 deletions(-)
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 5e42570af98..8b3e6b40fb4 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -6,7 +6,7 @@ import mill.main.buildgen.BuildGenUtil.*
 import mill.main.buildgen.IrDependencyType.*
 import os.Path
 
-import scala.collection.View
+import scala.collection.{MapView, View}
 import scala.collection.immutable.SortedSet
 
 /**
@@ -79,7 +79,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("Running sbt task to generate the project tree")
 
-    Process(
+    val exitCode = Process(
       Seq(
         sbtExecutable,
         s"-addPluginSbtFile=${writeSbtFile().toString}",
@@ -89,6 +89,10 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     ).!
 
     // println("Exit code from running the `millInitExportBuild` sbt task: " + exitCode)
+    if (exitCode != 0)
+      println(
+        "The sbt command to run the `millInitExportBuild` sbt task has likely failed, please update the project's sbt version to the latest or our tested version v1.10.7, and try again."
+      )
 
     val buildExportPickled = os.read(workspace / "target" / "mill-init-build-export.json")
     // TODO This is mainly for debugging purposes. Comment out this line if it's unnecessary.
@@ -300,21 +304,32 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     val allDepsByConfiguration = project.allDependencies
       // .view // This makes the types hard to deal with here thus commented out.
       .filterNot(isScalaStandardLibrary)
-      .groupBy(_.configurations match {
-        case None => Default
-        case Some(configuration) => configuration match {
-            case "compile" => Default
-            case "test" => Test
-            case "runtime" => Run
-            case "provided" | "optional" => Compile
+      .flatMap(dep =>
+        (dep.configurations match {
+          case None => Some(Default)
+          case Some(configuration) => configuration match {
+            case "compile" => Some(Default)
+            case "test" => Some(Test)
+            case "runtime" => Some(Run)
+            case "provided" | "optional" => Some(Compile)
+            case other =>
+              println(s"Dependency $dep with an unknown configuration ${escape(other)} is dropped.")
+              None
           }
-      })
+        })
+          .map(tpe => (dep, tpe))
+      )
+      .groupBy(_._2)
+      .view
+      .mapValues(_.map(_._1))
+      // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
+      .asInstanceOf[MapView[IrDependencyType, Seq[Dependency]]]
 
     case class Deps[I, M](ivy: Seq[I], module: Seq[M])
 
     // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
     val ivyAndModuleDepsByConfiguration: Map[IrDependencyType, Deps[Dependency, String]] =
-      allDepsByConfiguration.view.mapValues(deps => {
+      allDepsByConfiguration.mapValues(deps => {
         val tuple2 = deps.partitionMap(dep => {
           val id = groupArtifactVersion(dep)
           if (packages.isDefinedAt(id)) Right(packages(id))
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
new file mode 100644
index 00000000000..5535e285a56
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
@@ -0,0 +1,49 @@
+package build
+
+import $packages._
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule {
+
+  def artifactName = "sbt-multi-project-example"
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def pomSettings = PomSettings(
+    "sbt-multi-project-example",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+}
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
new file mode 100644
index 00000000000..a783fb2796a
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -0,0 +1,63 @@
+package build.common
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule with SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def ivyDeps = super.ivyDeps() ++ Agg(
+    ivy"ch.qos.logback:logback-classic:1.2.3",
+    ivy"com.typesafe.akka:akka-stream::2.5.6",
+    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.typesafe:config:1.3.1",
+    ivy"net.logstash.logback:logstash-logback-encoder:4.11",
+    ivy"org.slf4j:jcl-over-slf4j:1.7.25"
+  )
+
+  def pomSettings = PomSettings(
+    "common",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+  object test extends MavenTests with TestModule.ScalaTest {
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      ivy"org.scalacheck:scalacheck::1.13.5",
+      ivy"org.scalatest:scalatest::3.0.4"
+    )
+
+  }
+}
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
new file mode 100644
index 00000000000..5af49c4b576
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -0,0 +1,67 @@
+package build.multi1
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule with SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def ivyDeps = super.ivyDeps() ++ Agg(
+    ivy"ch.qos.logback:logback-classic:1.2.3",
+    ivy"com.github.julien-truffaut:monocle-core::1.4.0",
+    ivy"com.github.julien-truffaut:monocle-macro::1.4.0",
+    ivy"com.typesafe.akka:akka-stream::2.5.6",
+    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.typesafe:config:1.3.1",
+    ivy"net.logstash.logback:logstash-logback-encoder:4.11",
+    ivy"org.slf4j:jcl-over-slf4j:1.7.25"
+  )
+
+  def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+  def pomSettings = PomSettings(
+    "multi1",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+  object test extends MavenTests with TestModule.ScalaTest {
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      ivy"org.scalacheck:scalacheck::1.13.5",
+      ivy"org.scalatest:scalatest::3.0.4"
+    )
+
+  }
+}
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
new file mode 100644
index 00000000000..d42c7c8f864
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -0,0 +1,66 @@
+package build.multi2
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule with SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def ivyDeps = super.ivyDeps() ++ Agg(
+    ivy"ch.qos.logback:logback-classic:1.2.3",
+    ivy"com.github.pureconfig:pureconfig::0.8.0",
+    ivy"com.typesafe.akka:akka-stream::2.5.6",
+    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.typesafe:config:1.3.1",
+    ivy"net.logstash.logback:logstash-logback-encoder:4.11",
+    ivy"org.slf4j:jcl-over-slf4j:1.7.25"
+  )
+
+  def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+  def pomSettings = PomSettings(
+    "multi2",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+  object test extends MavenTests with TestModule.ScalaTest {
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      ivy"org.scalacheck:scalacheck::1.13.5",
+      ivy"org.scalatest:scalatest::3.0.4"
+    )
+
+  }
+}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index 667fcaa1a66..fc367bfebdf 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -110,7 +110,8 @@ lazy val compilerOptions = Seq(
 lazy val commonSettings = Seq(
   scalacOptions ++= compilerOptions,
   resolvers ++= Seq(
-    "Local Maven Repository" at "file://" + Path.userHome.absolutePath + "/.m2/repository",
+    // commented out as this is different on different machines
+    //"Local Maven Repository" at "file://" + Path.userHome.absolutePath + "/.m2/repository",
     Resolver.sonatypeRepo("releases"),
     Resolver.sonatypeRepo("snapshots")
   )
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties b/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
index 017bb86a23d..fe69360b7c0 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/project/build.properties
@@ -1 +1 @@
-sbt.version = 1.0.2
+sbt.version = 1.10.7

From ac9d6574ebd86888d759bdf80cc77e97069a3ea5 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 22:38:59 +0800
Subject: [PATCH 18/70] Generate the expected snapshots for
 "sbt-multi-project-example" with the config args, fixing some bugs

---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  24 +-
 .../sbt-multi-project-example/build.mill      | 248 ++++++++++++++++++
 .../src/mill/main/sbt/BuildGenTests.scala     |  14 +-
 3 files changed, 265 insertions(+), 21 deletions(-)
 create mode 100644 main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 8b3e6b40fb4..f5ea0b4c306 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -6,8 +6,8 @@ import mill.main.buildgen.BuildGenUtil.*
 import mill.main.buildgen.IrDependencyType.*
 import os.Path
 
-import scala.collection.{MapView, View}
 import scala.collection.immutable.SortedSet
+import scala.collection.{MapView, View}
 
 /**
  * Converts an sbt build to Mill by generating Mill build file(s).
@@ -164,7 +164,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       scalacOptions,
       pomSettings,
       publishVersion,
-      null, // not available in sbt as it seems
+      Seq.empty, // not available in sbt as it seems
       repositories
     )
 
@@ -198,7 +198,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       repositories = getRepositories(buildInfo).diff(baseInfo.repositories),
       javacOptions = getJavacOptions(buildInfo).diff(baseInfo.javacOptions),
       scalaVersion =
-        if (buildInfo.scalaVersion != baseInfo.scalaVersion) buildInfo.scalaVersion else null,
+        if (buildInfo.scalaVersion != baseInfo.scalaVersion) buildInfo.scalaVersion else None,
       scalacOptions = buildInfo.scalacOptions.map(scalacOptions =>
         baseInfo.scalacOptions.fold(scalacOptions)(baseScalacOptions =>
           scalacOptions.diff(baseScalacOptions)
@@ -308,14 +308,16 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
         (dep.configurations match {
           case None => Some(Default)
           case Some(configuration) => configuration match {
-            case "compile" => Some(Default)
-            case "test" => Some(Test)
-            case "runtime" => Some(Run)
-            case "provided" | "optional" => Some(Compile)
-            case other =>
-              println(s"Dependency $dep with an unknown configuration ${escape(other)} is dropped.")
-              None
-          }
+              case "compile" => Some(Default)
+              case "test" => Some(Test)
+              case "runtime" => Some(Run)
+              case "provided" | "optional" => Some(Compile)
+              case other =>
+                println(
+                  s"Dependency $dep with an unknown configuration ${escape(other)} is dropped."
+                )
+                None
+            }
         })
           .map(tpe => (dep, tpe))
       )
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
new file mode 100644
index 00000000000..9ecf8d78364
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -0,0 +1,248 @@
+package build
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object Deps {
+
+  val `ch.qos.logback:logback-classic` =
+    ivy"ch.qos.logback:logback-classic:1.2.3"
+
+  val `com.github.julien-truffaut:monocle-core` =
+    ivy"com.github.julien-truffaut:monocle-core::1.4.0"
+
+  val `com.github.julien-truffaut:monocle-macro` =
+    ivy"com.github.julien-truffaut:monocle-macro::1.4.0"
+
+  val `com.github.pureconfig:pureconfig` =
+    ivy"com.github.pureconfig:pureconfig::0.8.0"
+
+  val `com.typesafe.akka:akka-stream` =
+    ivy"com.typesafe.akka:akka-stream::2.5.6"
+
+  val `com.typesafe.scala-logging:scala-logging` =
+    ivy"com.typesafe.scala-logging:scala-logging::3.7.2"
+  val `com.typesafe:config` = ivy"com.typesafe:config:1.3.1"
+
+  val `net.logstash.logback:logstash-logback-encoder` =
+    ivy"net.logstash.logback:logstash-logback-encoder:4.11"
+  val `org.scalacheck:scalacheck` = ivy"org.scalacheck:scalacheck::1.13.5"
+  val `org.scalatest:scalatest` = ivy"org.scalatest:scalatest::3.0.4"
+  val `org.slf4j:jcl-over-slf4j` = ivy"org.slf4j:jcl-over-slf4j:1.7.25"
+}
+
+object `package` extends RootModule {
+
+  def artifactName = "sbt-multi-project-example"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def pomSettings = PomSettings(
+    "sbt-multi-project-example",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  object multi1 extends BaseModule {
+
+    def scalacOptions = super.scalacOptions() ++ Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation",
+      "-encoding",
+      "utf8"
+    )
+
+    def repositoriesTask = Task.Anon {
+      super.repositoriesTask() ++ Seq(
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/service/local/repositories/releases/content/"
+        ),
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/content/repositories/snapshots"
+        )
+      )
+    }
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.github.julien-truffaut:monocle-core`,
+      Deps.`com.github.julien-truffaut:monocle-macro`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+    def pomSettings = PomSettings(
+      "multi1",
+      "com.pbassiner",
+      "",
+      Seq(),
+      VersionControl(None, None, None, None),
+      Seq()
+    )
+
+    object tests extends MavenTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+
+  object multi2 extends BaseModule {
+
+    def scalacOptions = super.scalacOptions() ++ Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation",
+      "-encoding",
+      "utf8"
+    )
+
+    def repositoriesTask = Task.Anon {
+      super.repositoriesTask() ++ Seq(
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/service/local/repositories/releases/content/"
+        ),
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/content/repositories/snapshots"
+        )
+      )
+    }
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.github.pureconfig:pureconfig`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+    def pomSettings = PomSettings(
+      "multi2",
+      "com.pbassiner",
+      "",
+      Seq(),
+      VersionControl(None, None, None, None),
+      Seq()
+    )
+
+    object tests extends MavenTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+
+  object common extends BaseModule {
+
+    def scalacOptions = super.scalacOptions() ++ Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation",
+      "-encoding",
+      "utf8"
+    )
+
+    def repositoriesTask = Task.Anon {
+      super.repositoriesTask() ++ Seq(
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/service/local/repositories/releases/content/"
+        ),
+        coursier.maven.MavenRepository(
+          "https://oss.sonatype.org/content/repositories/snapshots"
+        )
+      )
+    }
+
+    def ivyDeps = super.ivyDeps() ++ Agg(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    def pomSettings = PomSettings(
+      "common",
+      "com.pbassiner",
+      "",
+      Seq(),
+      VersionControl(None, None, None, None),
+      Seq()
+    )
+
+    object tests extends MavenTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+}
+
+trait BaseModule extends SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def pomSettings = PomSettings(
+    "",
+    "com.pbassiner",
+    "",
+    Seq(),
+    VersionControl(None, None, None, None),
+    Seq()
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+}
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index 48e92fb127e..191ff33966b 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -25,17 +25,12 @@ object BuildGenTests extends TestSuite {
       )
     }
 
-    /*
-    test("config") {
-      val sourceRoot = os.sub / "application-library"
-      val expectedRoot = os.sub / "expected/config"
+    test("config-sbt-multi-project-example") {
+      val sourceRoot = os.sub / "sbt-multi-project-example"
+      val expectedRoot = os.sub / "expected/config/sbt-multi-project-example"
       val args = Array(
         "--base-module",
         "BaseModule",
-        "--base-project",
-        "utilities",
-        "--jvm-id",
-        "11",
         "--test-module",
         "tests",
         "--deps-object",
@@ -43,9 +38,8 @@ object BuildGenTests extends TestSuite {
         "--merge"
       )
       assert(
-        checker.check(GradleBuildGenMain.main(args), sourceRoot, expectedRoot)
+        checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot, true)
       )
     }
-     */
   }
 }

From f8d748b628a873fcba7eb6929fc53e484c8f5c5f Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 22:46:09 +0800
Subject: [PATCH 19/70] Set the settings in `ThisBuild` in
 "sbt-multi-project-example" so they are in the `BaseModule` in the generated
 build files

---
 .../sbt-multi-project-example/build.mill      | 115 ++++--------------
 .../sbt-multi-project-example/README.md       |   2 +
 .../sbt-multi-project-example/build.sbt       |  15 +--
 3 files changed, 31 insertions(+), 101 deletions(-)

diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index 9ecf8d78364..8e05b83b13e 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -37,29 +37,6 @@ object `package` extends RootModule {
 
   def artifactName = "sbt-multi-project-example"
 
-  def scalacOptions = super.scalacOptions() ++ Seq(
-    "-unchecked",
-    "-feature",
-    "-language:existentials",
-    "-language:higherKinds",
-    "-language:implicitConversions",
-    "-language:postfixOps",
-    "-deprecation",
-    "-encoding",
-    "utf8"
-  )
-
-  def repositoriesTask = Task.Anon {
-    super.repositoriesTask() ++ Seq(
-      coursier.maven.MavenRepository(
-        "https://oss.sonatype.org/service/local/repositories/releases/content/"
-      ),
-      coursier.maven.MavenRepository(
-        "https://oss.sonatype.org/content/repositories/snapshots"
-      )
-    )
-  }
-
   def pomSettings = PomSettings(
     "sbt-multi-project-example",
     "com.pbassiner",
@@ -71,29 +48,6 @@ object `package` extends RootModule {
 
   object multi1 extends BaseModule {
 
-    def scalacOptions = super.scalacOptions() ++ Seq(
-      "-unchecked",
-      "-feature",
-      "-language:existentials",
-      "-language:higherKinds",
-      "-language:implicitConversions",
-      "-language:postfixOps",
-      "-deprecation",
-      "-encoding",
-      "utf8"
-    )
-
-    def repositoriesTask = Task.Anon {
-      super.repositoriesTask() ++ Seq(
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/service/local/repositories/releases/content/"
-        ),
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/content/repositories/snapshots"
-        )
-      )
-    }
-
     def ivyDeps = super.ivyDeps() ++ Agg(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.julien-truffaut:monocle-core`,
@@ -126,29 +80,6 @@ object `package` extends RootModule {
 
   object multi2 extends BaseModule {
 
-    def scalacOptions = super.scalacOptions() ++ Seq(
-      "-unchecked",
-      "-feature",
-      "-language:existentials",
-      "-language:higherKinds",
-      "-language:implicitConversions",
-      "-language:postfixOps",
-      "-deprecation",
-      "-encoding",
-      "utf8"
-    )
-
-    def repositoriesTask = Task.Anon {
-      super.repositoriesTask() ++ Seq(
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/service/local/repositories/releases/content/"
-        ),
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/content/repositories/snapshots"
-        )
-      )
-    }
-
     def ivyDeps = super.ivyDeps() ++ Agg(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.pureconfig:pureconfig`,
@@ -180,29 +111,6 @@ object `package` extends RootModule {
 
   object common extends BaseModule {
 
-    def scalacOptions = super.scalacOptions() ++ Seq(
-      "-unchecked",
-      "-feature",
-      "-language:existentials",
-      "-language:higherKinds",
-      "-language:implicitConversions",
-      "-language:postfixOps",
-      "-deprecation",
-      "-encoding",
-      "utf8"
-    )
-
-    def repositoriesTask = Task.Anon {
-      super.repositoriesTask() ++ Seq(
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/service/local/repositories/releases/content/"
-        ),
-        coursier.maven.MavenRepository(
-          "https://oss.sonatype.org/content/repositories/snapshots"
-        )
-      )
-    }
-
     def ivyDeps = super.ivyDeps() ++ Agg(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.typesafe.akka:akka-stream`,
@@ -234,6 +142,18 @@ trait BaseModule extends SbtModule with PublishModule {
 
   def scalaVersion = "2.12.3"
 
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
   def pomSettings = PomSettings(
     "",
     "com.pbassiner",
@@ -245,4 +165,15 @@ trait BaseModule extends SbtModule with PublishModule {
 
   def publishVersion = "0.1.0-SNAPSHOT"
 
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
 }
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/README.md b/main/init/sbt/test/resources/sbt-multi-project-example/README.md
index 3c7a82b0293..4534701ff33 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/README.md
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/README.md
@@ -1,5 +1,7 @@
 # sbt-multi-project-example
 
+Adapted from <https://github.com/pbassiner/sbt-multi-project-example>.
+
 The goal of this example is to provide a multi-project build using `sbt` providing:
 * A single `build.sbt` file which allows for centralized configuration, dependency and build management
 * Each sub-project contains only its source code
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index fc367bfebdf..81f9e458450 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -91,7 +91,6 @@ lazy val commonDependencies = Seq(
 // SETTINGS
 
 lazy val settings =
-commonSettings ++
 wartremoverSettings ++
 scalafmtSettings
 
@@ -107,14 +106,12 @@ lazy val compilerOptions = Seq(
   "utf8"
 )
 
-lazy val commonSettings = Seq(
-  scalacOptions ++= compilerOptions,
-  resolvers ++= Seq(
-    // commented out as this is different on different machines
-    //"Local Maven Repository" at "file://" + Path.userHome.absolutePath + "/.m2/repository",
-    Resolver.sonatypeRepo("releases"),
-    Resolver.sonatypeRepo("snapshots")
-  )
+ThisBuild / scalacOptions ++= compilerOptions
+ThisBuild / resolvers ++= Seq(
+  // commented out as this is different on different machines
+  //"Local Maven Repository" at "file://" + Path.userHome.absolutePath + "/.m2/repository",
+  Resolver.sonatypeRepo("releases"),
+  Resolver.sonatypeRepo("snapshots")
 )
 
 lazy val wartremoverSettings = Seq(

From 4156577ec5f46fb7fb672010b4122cb966e66581 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 16 Feb 2025 23:54:12 +0800
Subject: [PATCH 20/70] Add POM settings in `ThisBuild` in
 "sbt-multi-project-example" to test the conversion, regenerate the snapshots,
 and fix a bug that `organizationHomepage` is passed as `IrPom.url` instead of
 `homepage` and regenerate again

Code related to `organizationHomepage` is commented out as it's actually unnecessary.
---
 .../sbt/models/src/mill/main/sbt/Models.scala |  3 +
 .../mill/main/sbt/ExportBuildPlugin.scala     |  2 +-
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  2 +-
 .../sbt-multi-project-example/build.mill      | 58 ++++++-------------
 .../sbt-multi-project-example/build.mill      | 22 +++++--
 .../common/package.mill                       | 22 +++++--
 .../multi1/package.mill                       | 22 +++++--
 .../multi2/package.mill                       | 22 +++++--
 .../sbt-multi-project-example/build.sbt       |  7 +++
 9 files changed, 97 insertions(+), 63 deletions(-)

diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index ae6a982ebac..68cedd06d07 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -62,12 +62,15 @@ case class BuildPublicationInfo(
      */
     organizationName: Option[String],
      */
+    // not needed
+    /*
     /**
      * corresponds to `organizationUrl` in POM
      *
      * @see [[Keys.organizationHomepage]]
      */
     organizationHomepage: Option[Option[String]],
+     */
     /** @see [[Keys.developers]] */
     developers: Option[Seq[Developer]],
     /** @see [[Keys.scmInfo]] */
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index f80705477e1..8597c6d5376 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -34,7 +34,7 @@ object ExportBuildPlugin extends AutoPlugin {
       }),
       organization.?.value,
       //organizationName.?.value, // not needed
-      organizationHomepage.?.value.map(_.map(_.toExternalForm)),
+      //organizationHomepage.?.value.map(_.map(_.toExternalForm)), // not needed
       developers.?.value.map(_.map(developer =>
         Developer(developer.id, developer.name, developer.email, developer.url.toExternalForm)
       )),
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index f5ea0b4c306..e6c3222f122 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -277,7 +277,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     IrPom(
       description.getOrElse(""),
       organization.getOrElse(""),
-      organizationHomepage.fold("")(_.getOrElse("")),
+      homepage.fold("")(_.getOrElse("")),
       licenses.getOrElse(Seq.empty).map(license => IrLicense(license._1, license._1, license._2)),
       scmInfo.flatten.fold(IrVersionControl(null, null, null, null))(scmInfo => {
         import scmInfo.*
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index 8e05b83b13e..def71c87d0c 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -37,15 +37,6 @@ object `package` extends RootModule {
 
   def artifactName = "sbt-multi-project-example"
 
-  def pomSettings = PomSettings(
-    "sbt-multi-project-example",
-    "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
-  )
-
   object multi1 extends BaseModule {
 
     def ivyDeps = super.ivyDeps() ++ Agg(
@@ -61,15 +52,6 @@ object `package` extends RootModule {
 
     def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
-    def pomSettings = PomSettings(
-      "multi1",
-      "com.pbassiner",
-      "",
-      Seq(),
-      VersionControl(None, None, None, None),
-      Seq()
-    )
-
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
@@ -92,15 +74,6 @@ object `package` extends RootModule {
 
     def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
-    def pomSettings = PomSettings(
-      "multi2",
-      "com.pbassiner",
-      "",
-      Seq(),
-      VersionControl(None, None, None, None),
-      Seq()
-    )
-
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
@@ -120,15 +93,6 @@ object `package` extends RootModule {
       Deps.`org.slf4j:jcl-over-slf4j`
     )
 
-    def pomSettings = PomSettings(
-      "common",
-      "com.pbassiner",
-      "",
-      Seq(),
-      VersionControl(None, None, None, None),
-      Seq()
-    )
-
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
@@ -155,12 +119,24 @@ trait BaseModule extends SbtModule with PublishModule {
   )
 
   def pomSettings = PomSettings(
-    "",
+    "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
   )
 
   def publishVersion = "0.1.0-SNAPSHOT"
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
index 5535e285a56..d2e18d855d0 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
@@ -36,12 +36,24 @@ object `package` extends RootModule {
   }
 
   def pomSettings = PomSettings(
-    "sbt-multi-project-example",
+    "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
   )
 
   def publishVersion = "0.1.0-SNAPSHOT"
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
index a783fb2796a..21acfc30af1 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -42,12 +42,24 @@ object `package` extends RootModule with SbtModule with PublishModule {
   )
 
   def pomSettings = PomSettings(
-    "common",
+    "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
   )
 
   def publishVersion = "0.1.0-SNAPSHOT"
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
index 5af49c4b576..408f966cd80 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -46,12 +46,24 @@ object `package` extends RootModule with SbtModule with PublishModule {
   def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
   def pomSettings = PomSettings(
-    "multi1",
+    "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
   )
 
   def publishVersion = "0.1.0-SNAPSHOT"
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
index d42c7c8f864..02a8ac8c169 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -45,12 +45,24 @@ object `package` extends RootModule with SbtModule with PublishModule {
   def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
   def pomSettings = PomSettings(
-    "multi2",
+    "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
-    "",
-    Seq(),
-    VersionControl(None, None, None, None),
-    Seq()
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
   )
 
   def publishVersion = "0.1.0-SNAPSHOT"
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index 81f9e458450..7ac330b18b3 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -2,6 +2,13 @@ name := "sbt-multi-project-example"
 organization in ThisBuild := "com.pbassiner"
 scalaVersion in ThisBuild := "2.12.3"
 
+val urlString = "https://github.com/com-lihaoyi/mill"
+ThisBuild / homepage := Some(url(urlString))
+ThisBuild / description := "This is an sbt sample project for testing Mill's init command."
+ThisBuild / licenses := Seq(License.Apache2)
+ThisBuild / developers := List(Developer("johnd", "John Doe", "john.doe@example.com", url("https://example.com/johnd")))
+ThisBuild / scmInfo := Some(ScmInfo(url(urlString), s"scm:git:$urlString.git"))
+
 // PROJECTS
 
 lazy val global = project

From f0d1378b40481c21d61743db85d86bb8dc2aab72 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 17 Feb 2025 00:02:26 +0800
Subject: [PATCH 21/70] Stop updating the expected test sample snapshots

---
 main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index 191ff33966b..3708220fe81 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -12,7 +12,7 @@ object BuildGenTests extends TestSuite {
       val sourceRoot = os.sub / "scala-seed-project"
       val expectedRoot = os.sub / "expected/scala-seed-project"
       assert(
-        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot, true)
+        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
       )
     }
 
@@ -21,7 +21,7 @@ object BuildGenTests extends TestSuite {
       val sourceRoot = os.sub / "sbt-multi-project-example"
       val expectedRoot = os.sub / "expected/sbt-multi-project-example"
       assert(
-        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot, true)
+        checker.check(SbtBuildGenMain.main(Array.empty), sourceRoot, expectedRoot)
       )
     }
 
@@ -38,7 +38,7 @@ object BuildGenTests extends TestSuite {
         "--merge"
       )
       assert(
-        checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot, true)
+        checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot)
       )
     }
   }

From ea780d7f43ca21aaaa7508ad6d3d97025788e92b Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 17 Feb 2025 00:52:11 +0800
Subject: [PATCH 22/70] Copy and adapt the docs and some code for sbt from
 those for Gradle referring to #4363

---
 dist/package.mill                             |   1 +
 docs/modules/ROOT/nav.adoc                    |   1 +
 docs/modules/ROOT/pages/migrating/sbt.adoc    | 120 ++++++++++++++++++
 .../mill/main/gradle/GradleBuildGenMain.scala |   3 +-
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  11 +-
 5 files changed, 130 insertions(+), 6 deletions(-)
 create mode 100644 docs/modules/ROOT/pages/migrating/sbt.adoc

diff --git a/dist/package.mill b/dist/package.mill
index f226bfe7999..1f40a9d299c 100644
--- a/dist/package.mill
+++ b/dist/package.mill
@@ -75,6 +75,7 @@ object `package` extends RootModule with InstallModule {
       build.main.graphviz.testDep(),
       build.main.init.maven.testDep(),
       build.main.init.gradle.testDep(),
+      build.main.init.sbt.testDep(),
       build.runner.linenumbers.testDep(),
       build.scalalib.backgroundwrapper.testDep(),
       build.contrib.bloop.testDep(),
diff --git a/docs/modules/ROOT/nav.adoc b/docs/modules/ROOT/nav.adoc
index ec9156fa191..658494ec3ca 100644
--- a/docs/modules/ROOT/nav.adoc
+++ b/docs/modules/ROOT/nav.adoc
@@ -58,6 +58,7 @@
 * xref:migrating/migrating.adoc[]
 ** xref:migrating/maven.adoc[]
 ** xref:migrating/gradle.adoc[]
+** xref:migrating/sbt.adoc[]
 // This section gives a tour of the various user-facing features of Mill:
 // library deps, out folder, queries, tasks, etc.. These are things that
 // every Mill user will likely encounter, and are touched upon in the various
diff --git a/docs/modules/ROOT/pages/migrating/sbt.adoc b/docs/modules/ROOT/pages/migrating/sbt.adoc
new file mode 100644
index 00000000000..5441f084c1c
--- /dev/null
+++ b/docs/modules/ROOT/pages/migrating/sbt.adoc
@@ -0,0 +1,120 @@
+= Migrating From sbt to Mill
+:page-aliases: Migrating_An_sbt_Build_to_Mill.adoc
+:icons: font
+
+
+
+The Mill `init` command can be used to convert an sbt build to Mill. This has
+xref:#limitations[limitations] and is not intended to reliably migrate 100% of
+sbt builds out there in the wild, but is instead meant to provide the basic
+scaffolding of a Mill build for you to further refine and update manually.
+
+Each sbt project in a build tree is converted to a Mill module.
+A nested `test` module is defined, if `src/test` exists, and is configured with a supported xref:scalalib/testing.adoc[test framework], if found.
+
+Again, note that `mill init` imports an sbt build on a best-effort basis.
+This means that while simple projects can be expected to complete without issue:
+
+include::partial$example/javalib/migrating/3-sbt-complete.adoc[]
+
+Projects with a complex build often require some manual tweaking in order to work:
+
+include::partial$example/javalib/migrating/4-sbt-incomplete.adoc[]
+
+== Capabilities
+
+The conversion
+
+* handles deeply nested modules
+* captures publish settings
+* configures dependencies for configurations:
+** no configuration
+** Compile
+** Test
+** Runtime
+** Provided
+** Optional
+* configures testing frameworks:
+** Java:
+*** JUnit 4
+*** JUnit 5
+*** TestNG
+** Scala:
+*** ScalaTest
+*** Specs2
+*** µTest
+*** MUnit
+*** Weaver
+*** ZIOTest
+
+[#arguments]
+=== Command line arguments
+
+The conversion and its output (the generated Mill build files) can be customized using
+
+* `--base-module` (`-b`): name of generated base module trait defining shared settings
++
+[source,sh]
+----
+./mill init --base-module MyModule
+----
+
+* `--test-module` (`-t`): name of generated nested test module (defaults to `test`)
++
+[source,sh]
+----
+./mill init --test-module test
+----
+
+* `--deps-object` (`-d`): name of generated companion object defining dependency constants
++
+[source,sh]
+----
+./mill init --deps-object Deps
+----
+
+* `--merge` (`-m`): merge build files generated for a multi-module build
++
+[source,sh]
+----
+./mill init --merge
+----
+
+TIP: You can run `mill init` multiple times. It is recommended to run it first without any options.
+
+[#limitations]
+== Limitations
+
+The conversion does not support:
+
+* custom dependency configurations
+* custom settings including custom tasks
+* sources other than Scala on JVM and Java
+
+sbt plugin support is limited to:
+
+* https://www.scala-sbt.org/1.x/api/sbt/plugins/JvmPlugin$.html[`JvmPlugin`]
+
+[TIP]
+====
+These limitations can be overcome by:
+
+* configuring equivalent Mill xref:extending/contrib-plugins.adoc[contrib]
+or xref:extending/thirdparty-plugins.adoc[third party] plugins
+* defining custom xref:extending/writing-plugins.adoc[plugins]
+* defining custom xref:fundamentals/tasks.adoc[tasks]
+* defining custom xref:fundamentals/cross-builds.adoc[cross modules]
+====
+
+== FAQ
+
+How to fix `java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release` error thrown by the sbt command invoked by `mill init`?
+
+Update the project's sbt version to the latest or our tested version v1.10.7, and try again.
+
+How to fix test compilation errors?
+
+* The test framework configured may be for an unsupported version; try upgrading the
+corresponding dependencies.
+* Mill does not add `compileIvyDeps` dependencies to the transitive dependencies of the nested
+test module; specify the dependencies again, in `ivyDeps` or `runIvyDeps`.
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index e6bf7b9dd33..66e40016cad 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -21,6 +21,7 @@ import scala.jdk.CollectionConverters.*
  * ===Capabilities===
  * The conversion
  *  - handles deeply nested modules
+ *  - captures publish settings
  *  - configures dependencies for configurations:
  *    - implementation / api
  *    - compileOnly / compileOnlyApi
@@ -33,7 +34,7 @@ import scala.jdk.CollectionConverters.*
  *    - TestNG
  *
  * ===Limitations===
- * The conversion does not support
+ * The conversion does not support:
  *  - custom dependency configurations
  *  - custom tasks
  *  - non-Java sources
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index e6c3222f122..159ab16dd34 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -20,13 +20,14 @@ import scala.collection.{MapView, View}
  * ===Capabilities===
  * The conversion
  *  - handles deeply nested modules
+ *  - captures publish settings
  *  - configures dependencies for configurations:
  *    - no configuration
  *    - Compile
+ *    - Test
+ *    - Runtime
  *    - Provided
  *    - Optional
- *    - Runtime
- *    - Test
  *  - configures testing frameworks (@see [[mill.scalalib.TestModule]]):
  *    - Java:
  *      - JUnit 4
@@ -40,9 +41,9 @@ import scala.collection.{MapView, View}
  *      - Weaver
  *      - ZIOTest
  * ===Limitations===
- * The conversion does not support
- *  - custom configurations
- *  - custom tasks
+ * The conversion does not support:
+ *  - custom dependency configurations
+ *  - custom settings including custom tasks
  *  - sources other than Scala on JVM and Java
  */
 @mill.api.internal

From b59e33f71e274336b5fe75166d369fb4eff2c090 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Tue, 18 Feb 2025 06:14:47 +0800
Subject: [PATCH 23/70] Copy and adapt the integration tests for sbt from those
 for Gradle, run them, review their results, and fix some bugs revealed

- Fix compiling issues in `MavenBuildGenMain.scala` and `GradleBuildGenMain.scala` caused by `scalaVersion` introduced.
- Copy the sbt plugin "sbt-mill-init-export-build-assembly.jar" to a temp directory to be consumed so it works in integration tests when Mill is packaged.
- Improve a message in `ExportBuildPlugin`.
- Make the generated `package` object always extends the `BaseModule` or `SbtModule` trait.
- Fix a bug in `renderIvy` that the double colon `::` is placed at the wrong place.
- Update the expected build file snapshots accordingly in test resources.
- Update docs.
---
 docs/modules/ROOT/pages/migrating/sbt.adoc    |   3 +-
 .../feature/init/src/MillInitSbtTests.scala   | 149 ++++++++++++++++++
 .../mill/main/gradle/GradleBuildGenMain.scala |   4 +
 .../mill/main/maven/MavenBuildGenMain.scala   |   4 +
 .../mill/main/sbt/ExportBuildPlugin.scala     |   2 +-
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  34 ++--
 .../sbt-multi-project-example/build.mill      |  16 +-
 .../sbt-multi-project-example/build.mill      |   2 +-
 .../common/package.mill                       |   8 +-
 .../multi1/package.mill                       |  12 +-
 .../multi2/package.mill                       |  10 +-
 .../expected/scala-seed-project/build.mill    |   2 +-
 12 files changed, 207 insertions(+), 39 deletions(-)
 create mode 100644 integration/feature/init/src/MillInitSbtTests.scala

diff --git a/docs/modules/ROOT/pages/migrating/sbt.adoc b/docs/modules/ROOT/pages/migrating/sbt.adoc
index 5441f084c1c..51c3956bae2 100644
--- a/docs/modules/ROOT/pages/migrating/sbt.adoc
+++ b/docs/modules/ROOT/pages/migrating/sbt.adoc
@@ -89,7 +89,8 @@ The conversion does not support:
 
 * custom dependency configurations
 * custom settings including custom tasks
-* sources other than Scala on JVM and Java
+* sources other than Scala on JVM and Java, such as Scala.js and Scala Native
+* cross builds
 
 sbt plugin support is limited to:
 
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
new file mode 100644
index 00000000000..183d8e50b5e
--- /dev/null
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -0,0 +1,149 @@
+package mill.integration
+
+import mill.integration.MillInitSbtTests.initCommand
+import utest.*
+
+object MillInitSbtTests {
+  val initCommand = ("init", "--base-module", "BaseModule", "--deps-object", "Deps", "--merge")
+}
+
+// Relatively large libraries
+
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtScalazTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 0.8 MB
+    - sbt 1.10.7
+     */
+    val url = "https://github.com/scalaz/scalaz/archive/refs/tags/v7.3.8.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtCatsTests extends BuildGenTestSuite {
+
+  def tests: Tests = Tests {
+    /*
+    - 2 MB
+    - sbt 1.10.7
+    - MUnit
+     */
+    val url = "https://github.com/typelevel/cats/archive/refs/tags/v2.13.0.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Converting child projects nested in a parent directory which is not a project is not supported yet.
+object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 5 MB
+    - sbt 1.10.5
+     */
+    val url = "https://github.com/playframework/playframework/archive/refs/tags/3.0.6.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
+
+  def tests: Tests = Tests {
+    /*
+    - 0.5 MB
+    - sbt 1.10.1
+     */
+    val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Relatively small libraries
+
+object MillInitScalaCsvTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 25 KB
+    - sbt 1.10.7
+     */
+    val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/2.0.0.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      // Cross builds are not supported yet.
+      assert(!compileResult.isSuccess)
+    }
+  }
+}
+
+// same as the one in the unit tests
+object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 10 KB
+     */
+    val url =
+      "https://github.com/pbassiner/sbt-multi-project-example/archive/152b31df9837115b183576b0080628b43c505389.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      // sbt version bumped so it works with JDK 21
+      os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+
+      val testResult = eval("test")
+      assert(testResult.isSuccess)
+    }
+  }
+}
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index 66e40016cad..4df87a053fc 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -125,6 +125,7 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
         Option.when(null != project.maven().pom()) { "PublishModule" }
 
     val javacOptions = getJavacOptions(project)
+    val scalaVersion = None
     val scalacOptions = None
     val repos = getRepositories(project)
     val pomSettings = extractPomSettings(project)
@@ -136,6 +137,7 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
       baseModule,
       supertypes,
       javacOptions,
+      scalaVersion,
       scalacOptions,
       pomSettings,
       publishVersion,
@@ -145,6 +147,7 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
 
     IrBaseInfo(
       javacOptions,
+      scalaVersion,
       scalacOptions,
       repos,
       pomSettings == null,
@@ -170,6 +173,7 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
       dirs = build.dirs,
       repositories = getRepositories(project).diff(baseInfo.repositories),
       javacOptions = getJavacOptions(project).diff(baseInfo.javacOptions),
+      scalaVersion = None,
       scalacOptions = None,
       projectName = getArtifactId(project),
       pomSettings = if (baseInfo.noPom) extractPomSettings(project) else null,
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index abfe12ae98f..d7b6b905039 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -67,6 +67,7 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
   ): IrBaseInfo = {
     val model = input.node.value
     val javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model)
+    val scalaVersion = None
     val scalacOptions = None
     val repositories = getRepositories(model)
     val pomSettings = extractPomSettings(model)
@@ -78,6 +79,7 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
       baseModule,
       getModuleSupertypes(cfg),
       javacOptions,
+      scalaVersion,
       scalacOptions,
       pomSettings,
       publishVersion,
@@ -87,6 +89,7 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
 
     IrBaseInfo(
       javacOptions,
+      scalaVersion,
       scalacOptions,
       repositories,
       noPom = false,
@@ -112,6 +115,7 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
       dirs = build.dirs,
       repositories = getRepositories(model),
       javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model).diff(baseInfo.javacOptions),
+      scalaVersion = None,
       scalacOptions = None,
       projectName = getArtifactId(model),
       pomSettings = if (baseInfo.noPom) extractPomSettings(model) else null,
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index 8597c6d5376..bc16baea4c9 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -103,7 +103,7 @@ object ExportBuildPlugin extends AutoPlugin {
               case Disabled => false
               case _: Binary => true
               case crossVersion =>
-                println(s"Unsupported `CrossVersion`: $crossVersion")
+                println(s"Dependency $moduleID with unsupported `CrossVersion`: $crossVersion")
                 false
             },
             moduleID.revision,
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 159ab16dd34..f21dc02dbfc 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -44,7 +44,8 @@ import scala.collection.{MapView, View}
  * The conversion does not support:
  *  - custom dependency configurations
  *  - custom settings including custom tasks
- *  - sources other than Scala on JVM and Java
+ *  - sources other than Scala on JVM and Java, such as Scala.js and Scala Native
+ *  - cross builds
  */
 @mill.api.internal
 object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[Node[Project]])] {
@@ -78,7 +79,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
         "No sbt executable (`./sbt`, `./sbtx`, or system-wide `sbt`) found"
       )
 
-    println("Running sbt task to generate the project tree")
+    println("Running the added `millInitExportBuild` sbt task to export the build")
 
     val exitCode = Process(
       Seq(
@@ -96,8 +97,8 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       )
 
     val buildExportPickled = os.read(workspace / "target" / "mill-init-build-export.json")
-    // TODO This is mainly for debugging purposes. Comment out this line if it's unnecessary.
-    println("sbt build export retrieved: " + buildExportPickled)
+    // TODO This is mainly for debugging purposes. Comment out or uncomment this line as needed.
+    // println("sbt build export retrieved: " + buildExportPickled)
     import upickle.default.*
     val buildExport = read[BuildExport](buildExportPickled)
 
@@ -112,6 +113,11 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
           Option.when(dirs.nonEmpty)(dirs.dropRight(1))
         })
 
+    /*
+    TODO This does not support converting child projects nested in a parent directory which is not a project yet.
+     Supporting this may involve refactoring `Node[Project]` into `Node[Option[Project]]`
+     or adding a subproject as a direct child with its ancestor directory project (I am not sure whether this works).
+     */
     val input = Tree.from(projectNodesByParentDirs(None).head) { node =>
       val dirs = node.dirs
       val children = projectNodesByParentDirs.getOrElse(Some(dirs), Seq.empty)
@@ -124,13 +130,20 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
   }
 
   private def writeSbtFile(): os.Path = {
-    val file = os.temp.dir() / "mill-init.sbt"
-    // TODO copy to a temp file if it doesn't work when packaged in a jar
+    val tempDir = os.temp.dir()
+    // This doesn't work in integration tests when Mill is packaged.
+    /*
     val sbtPluginJarUrl =
       getClass.getResource("/sbt-mill-init-export-build-assembly.jar").toExternalForm
+     */
+    val file = tempDir / "mill-init.sbt"
+    val sbtPluginJarName = "sbt-mill-init-export-build-assembly.jar"
+    val sbtPluginJarStream = getClass.getResourceAsStream(s"/$sbtPluginJarName")
+    val sbtPluginJarPath = tempDir / sbtPluginJarName
+    os.write(sbtPluginJarPath, sbtPluginJarStream)
     val contents =
       s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-export-build" % "dummy-version" from ${escape(
-          sbtPluginJarUrl
+          sbtPluginJarPath.wrapped.toUri.toString
         )})
          |""".stripMargin
     os.write(file, contents)
@@ -231,10 +244,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
   def getMillSourcePath(project: Project): Path = os.Path(project.projectDirectory)
 
   def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Project]): Seq[String] =
-    Seq("RootModule") ++
-      Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
-        getModuleSupertypes(cfg)
-      }.iterator.toSeq.flatten
+    Seq("RootModule") ++ getModuleSupertypes(cfg)
 
   def groupArtifactVersion(dep: Dependency): (String, String, String) =
     (dep.organization, dep.name, dep.revision)
@@ -254,7 +264,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
   def renderIvy(dependency: Dependency): String = {
     // type, classifier, and exclusions are not processed yet
     import dependency.*
-    s"ivy\"$organization:$name${if (crossVersion) "::" else ":"}$revision\""
+    s"ivy\"$organization${if (crossVersion) "::" else ":"}$name:$revision\""
   }
 
   def extractPomSettings(buildPublicationInfo: BuildPublicationInfo): IrPom = {
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index def71c87d0c..4eb6a02ebff 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -11,29 +11,29 @@ object Deps {
     ivy"ch.qos.logback:logback-classic:1.2.3"
 
   val `com.github.julien-truffaut:monocle-core` =
-    ivy"com.github.julien-truffaut:monocle-core::1.4.0"
+    ivy"com.github.julien-truffaut::monocle-core:1.4.0"
 
   val `com.github.julien-truffaut:monocle-macro` =
-    ivy"com.github.julien-truffaut:monocle-macro::1.4.0"
+    ivy"com.github.julien-truffaut::monocle-macro:1.4.0"
 
   val `com.github.pureconfig:pureconfig` =
-    ivy"com.github.pureconfig:pureconfig::0.8.0"
+    ivy"com.github.pureconfig::pureconfig:0.8.0"
 
   val `com.typesafe.akka:akka-stream` =
-    ivy"com.typesafe.akka:akka-stream::2.5.6"
+    ivy"com.typesafe.akka::akka-stream:2.5.6"
 
   val `com.typesafe.scala-logging:scala-logging` =
-    ivy"com.typesafe.scala-logging:scala-logging::3.7.2"
+    ivy"com.typesafe.scala-logging::scala-logging:3.7.2"
   val `com.typesafe:config` = ivy"com.typesafe:config:1.3.1"
 
   val `net.logstash.logback:logstash-logback-encoder` =
     ivy"net.logstash.logback:logstash-logback-encoder:4.11"
-  val `org.scalacheck:scalacheck` = ivy"org.scalacheck:scalacheck::1.13.5"
-  val `org.scalatest:scalatest` = ivy"org.scalatest:scalatest::3.0.4"
+  val `org.scalacheck:scalacheck` = ivy"org.scalacheck::scalacheck:1.13.5"
+  val `org.scalatest:scalatest` = ivy"org.scalatest::scalatest:3.0.4"
   val `org.slf4j:jcl-over-slf4j` = ivy"org.slf4j:jcl-over-slf4j:1.7.25"
 }
 
-object `package` extends RootModule {
+object `package` extends RootModule with BaseModule {
 
   def artifactName = "sbt-multi-project-example"
 
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
index d2e18d855d0..f5bb1ab05f6 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/build.mill
@@ -6,7 +6,7 @@ import mill.javalib._
 import mill.javalib.publish._
 import mill.scalalib.SbtModule
 
-object `package` extends RootModule {
+object `package` extends RootModule with SbtModule with PublishModule {
 
   def artifactName = "sbt-multi-project-example"
 
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
index 21acfc30af1..5fd5231ef42 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -34,8 +34,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def ivyDeps = super.ivyDeps() ++ Agg(
     ivy"ch.qos.logback:logback-classic:1.2.3",
-    ivy"com.typesafe.akka:akka-stream::2.5.6",
-    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.typesafe.akka::akka-stream:2.5.6",
+    ivy"com.typesafe.scala-logging::scala-logging:3.7.2",
     ivy"com.typesafe:config:1.3.1",
     ivy"net.logstash.logback:logstash-logback-encoder:4.11",
     ivy"org.slf4j:jcl-over-slf4j:1.7.25"
@@ -67,8 +67,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
   object test extends MavenTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Agg(
-      ivy"org.scalacheck:scalacheck::1.13.5",
-      ivy"org.scalatest:scalatest::3.0.4"
+      ivy"org.scalacheck::scalacheck:1.13.5",
+      ivy"org.scalatest::scalatest:3.0.4"
     )
 
   }
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
index 408f966cd80..289c6ad4c5e 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -34,10 +34,10 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def ivyDeps = super.ivyDeps() ++ Agg(
     ivy"ch.qos.logback:logback-classic:1.2.3",
-    ivy"com.github.julien-truffaut:monocle-core::1.4.0",
-    ivy"com.github.julien-truffaut:monocle-macro::1.4.0",
-    ivy"com.typesafe.akka:akka-stream::2.5.6",
-    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.github.julien-truffaut::monocle-core:1.4.0",
+    ivy"com.github.julien-truffaut::monocle-macro:1.4.0",
+    ivy"com.typesafe.akka::akka-stream:2.5.6",
+    ivy"com.typesafe.scala-logging::scala-logging:3.7.2",
     ivy"com.typesafe:config:1.3.1",
     ivy"net.logstash.logback:logstash-logback-encoder:4.11",
     ivy"org.slf4j:jcl-over-slf4j:1.7.25"
@@ -71,8 +71,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
   object test extends MavenTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Agg(
-      ivy"org.scalacheck:scalacheck::1.13.5",
-      ivy"org.scalatest:scalatest::3.0.4"
+      ivy"org.scalacheck::scalacheck:1.13.5",
+      ivy"org.scalatest::scalatest:3.0.4"
     )
 
   }
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
index 02a8ac8c169..539322907ea 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -34,9 +34,9 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def ivyDeps = super.ivyDeps() ++ Agg(
     ivy"ch.qos.logback:logback-classic:1.2.3",
-    ivy"com.github.pureconfig:pureconfig::0.8.0",
-    ivy"com.typesafe.akka:akka-stream::2.5.6",
-    ivy"com.typesafe.scala-logging:scala-logging::3.7.2",
+    ivy"com.github.pureconfig::pureconfig:0.8.0",
+    ivy"com.typesafe.akka::akka-stream:2.5.6",
+    ivy"com.typesafe.scala-logging::scala-logging:3.7.2",
     ivy"com.typesafe:config:1.3.1",
     ivy"net.logstash.logback:logstash-logback-encoder:4.11",
     ivy"org.slf4j:jcl-over-slf4j:1.7.25"
@@ -70,8 +70,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
   object test extends MavenTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Agg(
-      ivy"org.scalacheck:scalacheck::1.13.5",
-      ivy"org.scalatest:scalatest::3.0.4"
+      ivy"org.scalacheck::scalacheck:1.13.5",
+      ivy"org.scalatest::scalatest:3.0.4"
     )
 
   }
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index 27e391369ee..70b81474009 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -24,7 +24,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   object test extends MavenTests with TestModule.Munit {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(ivy"org.scalameta:munit::0.7.29")
+    def ivyDeps = super.ivyDeps() ++ Agg(ivy"org.scalameta::munit:0.7.29")
 
   }
 }

From 31154ac02590f5d1230d7452d235751eeccbdee7 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Tue, 18 Feb 2025 06:16:46 +0800
Subject: [PATCH 24/70] Add a TODO

---
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index f21dc02dbfc..eae0a42c3e4 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -262,7 +262,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
   // originally named `ivyInterp` in the Maven and module
   def renderIvy(dependency: Dependency): String = {
-    // type, classifier, and exclusions are not processed yet
+    // TODO type, classifier, and exclusions are not processed yet
     import dependency.*
     s"ivy\"$organization${if (crossVersion) "::" else ":"}$name:$revision\""
   }

From 3d2fafed6a2cdcbce2f8c6cc79a54e3c63e68e66 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 02:43:23 +0800
Subject: [PATCH 25/70] Add the example tests, and add more and rearrange the
 integration tests after manually running and tweaking them

---
 docs/modules/ROOT/pages/migrating/sbt.adoc    |   9 +-
 example/package.mill                          |   1 +
 .../migrating/1-sbt-complete/build.mill       |  26 +++
 .../migrating/2-sbt-incomplete/build.mill     |  35 ++++
 .../feature/init/src/MillInitSbtTests.scala   | 151 +++++++++++++-----
 .../sbt/models/src/mill/main/sbt/Models.scala |   2 +-
 6 files changed, 179 insertions(+), 45 deletions(-)
 create mode 100644 example/scalalib/migrating/1-sbt-complete/build.mill
 create mode 100644 example/scalalib/migrating/2-sbt-incomplete/build.mill

diff --git a/docs/modules/ROOT/pages/migrating/sbt.adoc b/docs/modules/ROOT/pages/migrating/sbt.adoc
index 51c3956bae2..825b0710296 100644
--- a/docs/modules/ROOT/pages/migrating/sbt.adoc
+++ b/docs/modules/ROOT/pages/migrating/sbt.adoc
@@ -15,11 +15,11 @@ A nested `test` module is defined, if `src/test` exists, and is configured with
 Again, note that `mill init` imports an sbt build on a best-effort basis.
 This means that while simple projects can be expected to complete without issue:
 
-include::partial$example/javalib/migrating/3-sbt-complete.adoc[]
+include::partial$example/scalalib/migrating/1-sbt-complete.adoc[]
 
 Projects with a complex build often require some manual tweaking in order to work:
 
-include::partial$example/javalib/migrating/4-sbt-incomplete.adoc[]
+include::partial$example/scalalib/migrating/2-sbt-incomplete.adoc[]
 
 == Capabilities
 
@@ -109,7 +109,10 @@ or xref:extending/thirdparty-plugins.adoc[third party] plugins
 
 == FAQ
 
-How to fix `java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release` error thrown by the sbt command invoked by `mill init`?
+How to fix errors such as
+`java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release` and
+`java.io.IOError: java.lang.RuntimeException: /packages cannot be represented as URI`
+thrown by the sbt command invoked by `mill init`?
 
 Update the project's sbt version to the latest or our tested version v1.10.7, and try again.
 
diff --git a/example/package.mill b/example/package.mill
index ea564d19c17..aee97163090 100644
--- a/example/package.mill
+++ b/example/package.mill
@@ -65,6 +65,7 @@ object `package` extends RootModule with Module {
     object publishing extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "publishing"))
     object web extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "web"))
     object native extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "native"))
+    object migrating extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "migrating"))
   }
   object javascriptlib extends Module {
     object basic extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "basic"))
diff --git a/example/scalalib/migrating/1-sbt-complete/build.mill b/example/scalalib/migrating/1-sbt-complete/build.mill
new file mode 100644
index 00000000000..5eb364e717a
--- /dev/null
+++ b/example/scalalib/migrating/1-sbt-complete/build.mill
@@ -0,0 +1,26 @@
+/** Usage
+
+ > rm build.mill # remove any existing build file
+
+ > git init .
+ > git remote add -f origin https://github.com/scalacenter/library-example.git
+ > git checkout v1.0.1
+
+ > ./mill init
+converting module library-example
+Dependency Dependency(com.lightbend.paradox,paradox-theme-generic,false,0.4.4,Some(paradox-theme)) with an unknown configuration "paradox-theme" is dropped.
+Dependency Dependency(com.lightbend.paradox,paradox-theme-generic,false,0.4.4,Some(paradox-theme)) with an unknown configuration "paradox-theme" is dropped.
+generated 1 Mill build file(s)
+removing existing Mill build files
+writing Mill build file to build.mill
+converted sbt build to Mill
+formatting Mill build files
+Formatting 1 Scala sources
+parsed config (v3.8.4): /var/folders/xh/9t7mxl615nv8627_v54lc9ph0000gn/T/3390681381000847719.tmp
+init completed, run "mill resolve _" to list available tasks
+
+ > ./mill compile
+ [46/46] compile
+ [46] [info] compiling 1 Scala source to /.../libsam/out/compile.dest/classes ...
+ [46] [info] done compiling
+*/
diff --git a/example/scalalib/migrating/2-sbt-incomplete/build.mill b/example/scalalib/migrating/2-sbt-incomplete/build.mill
new file mode 100644
index 00000000000..1508ddbdd3b
--- /dev/null
+++ b/example/scalalib/migrating/2-sbt-incomplete/build.mill
@@ -0,0 +1,35 @@
+/** Usage
+
+> rm build.mill # remove any existing build file
+
+> git init .
+> git remote add -f origin https://github.com/tototoshi/scala-csv.git
+> git checkout 2.0.0
+
+> ./mill init
+converting sbt build
+Running the added `millInitExportBuild` sbt task to export the build
+[info] welcome to sbt 1.10.0 (Eclipse Adoptium Java 17.0.14)
+[info] loading settings for project test-build from plugins.sbt,mill-init.sbt ...
+[info] loading project definition from /.../project
+[info] loading settings for project test from build.sbt,doctest.sbt ...
+[info] set current project to scala-csv (in build file:/.../)
+[success] Total time: 0 s, completed Feb 19, 2025, 1:42:45 AM
+converting module scala-csv
+generated 1 Mill build file(s)
+removing existing Mill build files
+writing Mill build file to build.mill
+converted sbt build to Mill
+formatting Mill build files
+Formatting 1 Scala sources
+parsed config (v3.8.4): /var/folders/xh/9t7mxl615nv8627_v54lc9ph0000gn/T/17040603558958375710.tmp
+init completed, run "mill resolve _" to list available tasks
+
+> ./mill compile # You will have to further configure the `CrossScalaModule` for different Scala versions
+ [46/46] compile
+ [46] [info] compiling 7 Scala sources and 3 Java sources to /.../out/compile.dest/classes ...
+ [46] [error] /.../src/main/scala/com/github/tototoshi/csv/CSVReader.scala:24:115: not found: type CSVReaderCompat
+ [46] [error] class CSVReader protected (private val lineReader: LineReader)(implicit format: CSVFormat) extends Closeable with CSVReaderCompat {
+ [46] [error]                                                                                                                   ^
+ [46] [error] one error found
+*/
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 183d8e50b5e..14017277173 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -1,28 +1,28 @@
 package mill.integration
 
-import mill.integration.MillInitSbtTests.initCommand
+import mill.integration.MillInitSbtTests.{bumpSbtTo1107, initCommand}
 import utest.*
 
 object MillInitSbtTests {
   val initCommand = ("init", "--base-module", "BaseModule", "--deps-object", "Deps", "--merge")
+  def bumpSbtTo1107(workspacePath: os.Path) =
+    // bump sbt version to resolve compatibility issues with lower sbt versions and higher JDK versions
+    os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
 }
 
-// Relatively large libraries
+// relatively small libraries
 
-// Scala.js and scala-native projects are not properly imported
-object MillInitSbtScalazTests extends BuildGenTestSuite {
+object MillInitLibraryExampleTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 0.8 MB
-    - sbt 1.10.7
+    - 21 KB
+    - sbt 1.5.2
      */
-    val url = "https://github.com/scalaz/scalaz/archive/refs/tags/v7.3.8.zip"
+    val url = "https://github.com/scalacenter/library-example/archive/refs/tags/v1.0.1.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
-      os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
-
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
@@ -32,59 +32,87 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
   }
 }
 
-// Scala.js and scala-native projects are not properly imported
-object MillInitSbtCatsTests extends BuildGenTestSuite {
-
+object MillInitScalaCsv200Tests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 2 MB
+    - 34 KB
     - sbt 1.10.7
-    - MUnit
      */
-    val url = "https://github.com/typelevel/cats/archive/refs/tags/v2.13.0.zip"
+    val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/2.0.0.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
+
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      // Cross builds are not supported yet.
+      assert(!compileResult.isSuccess)
+    }
+  }
+}
+
+object MillInitScalaCsv136Tests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 28 KB
+    - originally sbt 1.2.8
+     */
+    val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/1.3.6.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      bumpSbtTo1107(workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
+      // It works here, but scala 2.11 with JDK 6 seems not supported when run with JDK 17 in shell.
       assert(compileResult.isSuccess)
     }
   }
 }
 
-// Converting child projects nested in a parent directory which is not a project is not supported yet.
-object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
+// same as the one in the unit tests
+object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 5 MB
-    - sbt 1.10.5
+    - 10 KB
+    - originally sbt 1.0.2
      */
-    val url = "https://github.com/playframework/playframework/archive/refs/tags/3.0.6.zip"
+    val url =
+      "https://github.com/pbassiner/sbt-multi-project-example/archive/152b31df9837115b183576b0080628b43c505389.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      bumpSbtTo1107(workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
+
+      // Submodules don't compile well, which seems to be due to incompatible bytecode versions in dependencies.
+      val compileSubmodulesResult = eval("_.compile")
+      assert(!compileSubmodulesResult.isSuccess)
     }
   }
 }
 
-// Scala.js and scala-native projects are not properly imported
-object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
+// relatively large libraries
 
+object MillInitZioHttpTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 0.5 MB
-    - sbt 1.10.1
+    - 1.4 MB
+    - sbt 1.10.6
      */
-    val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"
+    val url = "https://github.com/zio/zio-http/archive/refs/tags/v3.0.1.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
@@ -94,56 +122,97 @@ object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
 
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
+
+      val compileSubmodulesResult = eval("_.compile")
+      // Some dependencies with currently unsupported `CrossVersion` `For3Use2_13` are not imported properly
+      assert(!compileSubmodulesResult.isSuccess)
     }
   }
 }
 
-// Relatively small libraries
-
-object MillInitScalaCsvTests extends BuildGenTestSuite {
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtScalazTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 25 KB
+    - 0.8 MB
     - sbt 1.10.7
      */
-    val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/2.0.0.zip"
+    val url = "https://github.com/scalaz/scalaz/archive/refs/tags/v7.3.8.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
-      // Cross builds are not supported yet.
-      assert(!compileResult.isSuccess)
+      assert(compileResult.isSuccess)
     }
   }
 }
 
-// same as the one in the unit tests
-object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtCatsTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 10 KB
+    - 2 MB
+    - sbt 1.10.7
+    - MUnit
      */
-    val url =
-      "https://github.com/pbassiner/sbt-multi-project-example/archive/152b31df9837115b183576b0080628b43c505389.zip"
+    val url = "https://github.com/typelevel/cats/archive/refs/tags/v2.13.0.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
-      // sbt version bumped so it works with JDK 21
-      os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Converting child projects nested in a parent directory which is not a project is not supported yet.
+object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 5 MB
+    - sbt 1.10.5
+     */
+    val url = "https://github.com/playframework/playframework/archive/refs/tags/3.0.6.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
 
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
+    }
+  }
+}
+
+// Scala.js and scala-native projects are not properly imported
+object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
+  def tests: Tests = Tests {
+    /*
+    - 0.5 MB
+    - sbt 1.10.1
+     */
+    val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"
+
+    test - integrationTest(url) { tester =>
+      import tester.*
 
-      val testResult = eval("test")
-      assert(testResult.isSuccess)
+      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      assert(initResult.isSuccess)
+
+      val compileResult = eval("compile")
+      assert(compileResult.isSuccess)
     }
   }
 }
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 68cedd06d07..9fb9d7e8812 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -131,7 +131,7 @@ object Project {
 case class Dependency(
     organization: String, // `groupId` in Maven
     name: String, // `artifactId` in Maven
-    crossVersion: Boolean = false,
+    crossVersion: Boolean = false, // TODO support `CrossVersion` types other than binary?
     revision: String,
     configurations: Option[String]
     // BOM seems not supported by sbt. See https://stackoverflow.com/questions/42032303/how-do-i-use-a-maven-bom-bill-of-materials-to-manage-my-dependencies-in-sbt.

From 44f6ada53212ba0e0f123334f2a5013d43147d21 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 17:58:06 +0800
Subject: [PATCH 26/70] Set up sbt in the CI to fix the failing CI tests

---
 .github/actions/pre-build-setup/action.yml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/.github/actions/pre-build-setup/action.yml b/.github/actions/pre-build-setup/action.yml
index 585dc24d21b..85608ea991c 100644
--- a/.github/actions/pre-build-setup/action.yml
+++ b/.github/actions/pre-build-setup/action.yml
@@ -65,4 +65,6 @@ runs:
     - uses: actions/checkout@v4
 
     - run: echo temurin:${{ inputs.java-version }} > .mill-jvm-version
-      shell: bash
\ No newline at end of file
+      shell: bash
+
+    - uses: sbt/setup-sbt@v1

From 802f0057237bf0f96f6b5d1541953a206d900fdf Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 18:37:22 +0800
Subject: [PATCH 27/70] Move `setup-sbt` to `post-build-setup`

---
 .github/actions/post-build-setup/action.yml | 4 +++-
 .github/actions/pre-build-setup/action.yml  | 2 --
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/actions/post-build-setup/action.yml b/.github/actions/post-build-setup/action.yml
index ab854420f53..63ee9c9c38e 100644
--- a/.github/actions/post-build-setup/action.yml
+++ b/.github/actions/post-build-setup/action.yml
@@ -34,4 +34,6 @@ runs:
         name: ${{ inputs.os }}-selective-execution-artifact
 
     - run: mv out/mill-selective-execution/mill-selective-execution.json out/mill-selective-execution.json
-      shell: bash
\ No newline at end of file
+      shell: bash
+
+    - uses: sbt/setup-sbt@v1
diff --git a/.github/actions/pre-build-setup/action.yml b/.github/actions/pre-build-setup/action.yml
index 85608ea991c..720e58df130 100644
--- a/.github/actions/pre-build-setup/action.yml
+++ b/.github/actions/pre-build-setup/action.yml
@@ -66,5 +66,3 @@ runs:
 
     - run: echo temurin:${{ inputs.java-version }} > .mill-jvm-version
       shell: bash
-
-    - uses: sbt/setup-sbt@v1

From 39baa2dc5980477d60a39c4eb51a6fb3403c26eb Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 18:47:42 +0800
Subject: [PATCH 28/70] Refine a TODO

---
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index eae0a42c3e4..3e286818dfe 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -262,7 +262,11 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
   // originally named `ivyInterp` in the Maven and module
   def renderIvy(dependency: Dependency): String = {
-    // TODO type, classifier, and exclusions are not processed yet
+    /*
+    TODO `type, `classifier`, and `exclusions` are not processed yet.
+     Processing them involves extracting information from `ModuleID.explicitArtifacts`
+     which is a `Vector` of `sbt.librarymanagement.Artifact` and `sbt.librarymanagement.InclExclRule`s.
+     */
     import dependency.*
     s"ivy\"$organization${if (crossVersion) "::" else ":"}$name:$revision\""
   }

From 3db82884d3a016664804885a923a81b797cfbad6 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 19:48:27 +0800
Subject: [PATCH 29/70] Fix compiling and test issues after the merge

The following tests are fixed:

* `./mill main.init.test`
* `./mill main.init.sbt.test`
* `./mill 'integration.feature[init].packaged.server'`

Expected snapshots in test resource are updated accordingly.
---
 .../config/sbt-multi-project-example/build.mill      | 12 ++++++------
 .../sbt-multi-project-example/common/package.mill    |  4 ++--
 .../sbt-multi-project-example/multi1/package.mill    |  4 ++--
 .../sbt-multi-project-example/multi2/package.mill    |  4 ++--
 .../resources/expected/scala-seed-project/build.mill |  2 +-
 main/init/src/mill/init/InitSbtModule.scala          |  6 +++---
 main/src/mill/main/MainModule.scala                  |  3 +--
 7 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index 4eb6a02ebff..4807d5264e1 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -39,7 +39,7 @@ object `package` extends RootModule with BaseModule {
 
   object multi1 extends BaseModule {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.julien-truffaut:monocle-core`,
       Deps.`com.github.julien-truffaut:monocle-macro`,
@@ -55,14 +55,14 @@ object `package` extends RootModule with BaseModule {
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
-        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
 
     }
   }
 
   object multi2 extends BaseModule {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.pureconfig:pureconfig`,
       Deps.`com.typesafe.akka:akka-stream`,
@@ -77,14 +77,14 @@ object `package` extends RootModule with BaseModule {
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
-        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
 
     }
   }
 
   object common extends BaseModule {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.typesafe.akka:akka-stream`,
       Deps.`com.typesafe.scala-logging:scala-logging`,
@@ -96,7 +96,7 @@ object `package` extends RootModule with BaseModule {
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
-        Agg(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
 
     }
   }
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
index 5fd5231ef42..d95ee7c1d5e 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -32,7 +32,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
     )
   }
 
-  def ivyDeps = super.ivyDeps() ++ Agg(
+  def ivyDeps = super.ivyDeps() ++ Seq(
     ivy"ch.qos.logback:logback-classic:1.2.3",
     ivy"com.typesafe.akka::akka-stream:2.5.6",
     ivy"com.typesafe.scala-logging::scala-logging:3.7.2",
@@ -66,7 +66,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   object test extends MavenTests with TestModule.ScalaTest {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
       ivy"org.scalatest::scalatest:3.0.4"
     )
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
index 289c6ad4c5e..80aea6a7077 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -32,7 +32,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
     )
   }
 
-  def ivyDeps = super.ivyDeps() ++ Agg(
+  def ivyDeps = super.ivyDeps() ++ Seq(
     ivy"ch.qos.logback:logback-classic:1.2.3",
     ivy"com.github.julien-truffaut::monocle-core:1.4.0",
     ivy"com.github.julien-truffaut::monocle-macro:1.4.0",
@@ -70,7 +70,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   object test extends MavenTests with TestModule.ScalaTest {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
       ivy"org.scalatest::scalatest:3.0.4"
     )
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
index 539322907ea..c5df60d3df4 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -32,7 +32,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
     )
   }
 
-  def ivyDeps = super.ivyDeps() ++ Agg(
+  def ivyDeps = super.ivyDeps() ++ Seq(
     ivy"ch.qos.logback:logback-classic:1.2.3",
     ivy"com.github.pureconfig::pureconfig:0.8.0",
     ivy"com.typesafe.akka::akka-stream:2.5.6",
@@ -69,7 +69,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   object test extends MavenTests with TestModule.ScalaTest {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(
+    def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
       ivy"org.scalatest::scalatest:3.0.4"
     )
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index 70b81474009..a605637f48e 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -24,7 +24,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   object test extends MavenTests with TestModule.Munit {
 
-    def ivyDeps = super.ivyDeps() ++ Agg(ivy"org.scalameta::munit:0.7.29")
+    def ivyDeps = super.ivyDeps() ++ Seq(ivy"org.scalameta::munit:0.7.29")
 
   }
 }
diff --git a/main/init/src/mill/init/InitSbtModule.scala b/main/init/src/mill/init/InitSbtModule.scala
index 4cf6dbd064a..fa55853a950 100644
--- a/main/init/src/mill/init/InitSbtModule.scala
+++ b/main/init/src/mill/init/InitSbtModule.scala
@@ -1,14 +1,14 @@
 package mill.init
 
 import mill.T
-import mill.api.{Loose, PathRef}
+import mill.api.PathRef
 import mill.define.{Discover, ExternalModule}
 
 @mill.api.experimental
 object InitSbtModule extends ExternalModule with BuildGenModule {
-  lazy val millDiscover: Discover = Discover[this.type]
+  lazy val millDiscover = Discover[this.type]
 
-  def buildGenClasspath: T[Loose.Agg[PathRef]] = BuildGenModule.millModule("mill-main-init-sbt")
+  def buildGenClasspath: T[Seq[PathRef]] = BuildGenModule.millModule("mill-main-init-sbt")
 
   def buildGenMainClass: T[String] = "mill.main.sbt.SbtBuildGenMain"
 }
diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index 449a0b88503..2f6c126b71e 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -279,8 +279,7 @@ trait MainModule extends BaseModule {
             SelectMode.Separated
           )
         else if (os.exists(os.pwd / "build.sbt"))
-          RunScript.evaluateTasksNamed(
-            evaluator,
+          evaluator.resolveEvaluate(
             Seq("mill.init.InitSbtModule/init") ++ args,
             SelectMode.Separated
           )

From 918359e5d649f7cd6df809206c3c4f34bb8beb21 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 19 Feb 2025 21:54:00 +0800
Subject: [PATCH 30/70] Split the `sbt assembly` command into a tuple, and
 replace `scala.sys.process` APIs with `os.call` APIs for consistency

---
 main/init/package.mill                                | 9 ++++-----
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala | 8 ++++----
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/main/init/package.mill b/main/init/package.mill
index 90ff867d9c4..811626b8758 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -107,14 +107,13 @@ object `package` extends RootModule with build.MillPublishScalaModule {
 
       sbtPluginProjectSource()
 
-      import scala.sys.process._
       val version = build.millVersion()
       if (
-        Process(
+        os.call(
           // The version is passed to the sbt build so it correctly resolves the "models" dependency version and sets its own version.
-          s"""sbt 'set version := "$version"' assembly""",
-          sbtPluginProjectPath.toIO
-        ).! != 0
+          ("sbt", s"""set version := "$version"""", "assembly"),
+          cwd = sbtPluginProjectPath
+        ).exitCode != 0
       )
         throw new RuntimeException(
           "Failed to run `sbt assembly` in the \"sbt-mill-init-export-build\" sbt project. " +
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 3e286818dfe..2a3103aa897 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -71,7 +71,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       "./sbtx"
     else if (
       // The return code is somehow 1 instead of 0.
-      Seq("sbt", "--help").!(ProcessLogger(_ => ())) == 1
+      os.call(("sbt", "--help"), check = false).exitCode == 1
     )
       "sbt"
     else
@@ -81,14 +81,14 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("Running the added `millInitExportBuild` sbt task to export the build")
 
-    val exitCode = Process(
+    val exitCode = os.call(
       Seq(
         sbtExecutable,
         s"-addPluginSbtFile=${writeSbtFile().toString}",
         "millInitExportBuild"
       ),
-      workspace.toIO
-    ).!
+      cwd = workspace
+    ).exitCode
 
     // println("Exit code from running the `millInitExportBuild` sbt task: " + exitCode)
     if (exitCode != 0)

From 4419d7fd1b7d398f02917a8292e63e94d132feee Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 01:18:46 +0800
Subject: [PATCH 31/70] Fix calling the sbt command in the
 `sbtPluginJarResources` Mill task on Windows, and try fixing a similar issue
 in `SbtBuildGenMain`

The command `sbt -addPluginSbtFile=test.sbt` doesn't run properly on my Windows machine with the following error:
```text
[error] Expected ':'
[error] Expected '='
[error] Expected whitespace character
[error] -addPluginSbtFile
[error]                  ^

```

`./mill main.init.sbt.test` fails with the error above in all 3 tests too.
---
 main/init/package.mill                         |  7 +++++--
 .../src/mill/main/sbt/SbtBuildGenMain.scala    | 18 ++++++++----------
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/main/init/package.mill b/main/init/package.mill
index 811626b8758..716171fc646 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -107,12 +107,15 @@ object `package` extends RootModule with build.MillPublishScalaModule {
 
       sbtPluginProjectSource()
 
+      val isWindows = System.getProperty("os.name").toLowerCase.startsWith("windows")
       val version = build.millVersion()
       if (
         os.call(
           // The version is passed to the sbt build so it correctly resolves the "models" dependency version and sets its own version.
-          ("sbt", s"""set version := "$version"""", "assembly"),
-          cwd = sbtPluginProjectPath
+          if (isWindows) ("sbt.bat", s"""set version := \\"$version\\"""", "assembly")
+          else ("sbt", s"""set version := "$version"""", "assembly"),
+          cwd = sbtPluginProjectPath,
+          stdout = os.Inherit
         ).exitCode != 0
       )
         throw new RuntimeException(
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 2a3103aa897..5637fdb01c4 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -1,6 +1,7 @@
 package mill.main.sbt
 
 import mainargs.{ParserForClass, main}
+import mill.constants.Util
 import mill.main.buildgen.*
 import mill.main.buildgen.BuildGenUtil.*
 import mill.main.buildgen.IrDependencyType.*
@@ -61,7 +62,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("converting sbt build")
 
-    import scala.sys.process.*
+    val systemSbt = if (Util.isWindows) "sbt.bat" else "sbt"
 
     // resolve the sbt executable
     // https://raw.githubusercontent.com/paulp/sbt-extras/master/sbt
@@ -71,23 +72,20 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       "./sbtx"
     else if (
       // The return code is somehow 1 instead of 0.
-      os.call(("sbt", "--help"), check = false).exitCode == 1
+      os.call((systemSbt, "--help"), check = false).exitCode == 1
     )
-      "sbt"
+      systemSbt
     else
       throw new RuntimeException(
-        "No sbt executable (`./sbt`, `./sbtx`, or system-wide `sbt`) found"
+        s"No sbt executable (`./sbt`, `./sbtx`, or system-wide `$systemSbt`) found"
       )
 
     println("Running the added `millInitExportBuild` sbt task to export the build")
 
     val exitCode = os.call(
-      Seq(
-        sbtExecutable,
-        s"-addPluginSbtFile=${writeSbtFile().toString}",
-        "millInitExportBuild"
-      ),
-      cwd = workspace
+      (sbtExecutable, s"-addPluginSbtFile=${writeSbtFile().toString}", "millInitExportBuild"),
+      cwd = workspace,
+      stdout = os.Inherit
     ).exitCode
 
     // println("Exit code from running the `millInitExportBuild` sbt task: " + exitCode)

From 68d830f670ba552c278a8149f4d05264839643a7 Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 02:44:14 +0800
Subject: [PATCH 32/70] Get the `sbt millInitExportBuild` command to work on
 Windows with a workaround of putting the ".sbt" file directly in the sbt
 "project" directory

`main.init.sbt.test.test` result:
```text
Tests: 3, Passed: 2, Failed: 1
```
---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 66 +++++++++++++++----
 1 file changed, 53 insertions(+), 13 deletions(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 5637fdb01c4..d4d9907f4a1 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -62,7 +62,8 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("converting sbt build")
 
-    val systemSbt = if (Util.isWindows) "sbt.bat" else "sbt"
+    val isWindows = Util.isWindows
+    val systemSbt = if (isWindows) "sbt.bat" else "sbt"
 
     // resolve the sbt executable
     // https://raw.githubusercontent.com/paulp/sbt-extras/master/sbt
@@ -82,11 +83,35 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("Running the added `millInitExportBuild` sbt task to export the build")
 
-    val exitCode = os.call(
-      (sbtExecutable, s"-addPluginSbtFile=${writeSbtFile().toString}", "millInitExportBuild"),
-      cwd = workspace,
-      stdout = os.Inherit
-    ).exitCode
+    val exitCode = (
+      if (isWindows) {
+        /*
+        `-addPluginSbtFile` somehow doesn't work on Windows, therefore, the ".sbt" file is put directly in the sbt "project" directory.
+        The error message:
+        ```text
+        [error] Expected ':'
+        [error] Expected '='
+        [error] Expected whitespace character
+        [error] -addPluginSbtFile
+        [error]                  ^
+        ```
+         */
+        val sbtFile = writeTempSbtFileInSbtProjectDirectory(workspace)
+        val commandResult = os.call(
+          (sbtExecutable, "millInitExportBuild"),
+          cwd = workspace,
+          stdout = os.Inherit
+        )
+        os.remove(sbtFile)
+        commandResult
+      } else
+        os.call(
+          (sbtExecutable, s"-addPluginSbtFile=${writeSbtFile().toString}", "millInitExportBuild"),
+          cwd = workspace,
+          stdout = os.Inherit
+        )
+    )
+    .exitCode
 
     // println("Exit code from running the `millInitExportBuild` sbt task: " + exitCode)
     if (exitCode != 0)
@@ -127,27 +152,42 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     println("converted sbt build to Mill")
   }
 
-  private def writeSbtFile(): os.Path = {
+  /**
+   * @return the temp directory the jar is in and the sbt file contents.
+   */
+  private def copyExportBuildAssemblyJarOutAndGetSbtFileContents(): (os.Path, String) = {
     val tempDir = os.temp.dir()
     // This doesn't work in integration tests when Mill is packaged.
     /*
     val sbtPluginJarUrl =
       getClass.getResource("/sbt-mill-init-export-build-assembly.jar").toExternalForm
      */
-    val file = tempDir / "mill-init.sbt"
     val sbtPluginJarName = "sbt-mill-init-export-build-assembly.jar"
     val sbtPluginJarStream = getClass.getResourceAsStream(s"/$sbtPluginJarName")
     val sbtPluginJarPath = tempDir / sbtPluginJarName
     os.write(sbtPluginJarPath, sbtPluginJarStream)
     val contents =
-      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-export-build" % "dummy-version" from ${escape(
-          sbtPluginJarPath.wrapped.toUri.toString
-        )})
+      s"""addSbtPlugin("com.lihaoyi" % "mill-main-init-sbt-sbt-mill-init-export-build" % "dummy-version" from ${
+          escape(sbtPluginJarPath.wrapped.toUri.toString)
+        })
          |""".stripMargin
-    os.write(file, contents)
-    file
+    (tempDir, contents)
   }
 
+  private def writeSbtFile(): os.Path = {
+    val (tempDir, contents) = copyExportBuildAssemblyJarOutAndGetSbtFileContents()
+    val sbtFile = tempDir / "mill-init.sbt"
+    os.write(sbtFile, contents)
+    sbtFile
+  }
+
+  private def writeTempSbtFileInSbtProjectDirectory(workspace: os.Path) =
+    os.temp(
+      copyExportBuildAssemblyJarOutAndGetSbtFileContents()._2,
+      workspace / "project",
+      suffix = ".sbt"
+    )
+
   override def getProjectTree(input: (BuildInfo, Tree[Node[Project]])): Tree[Node[Project]] =
     input._2
 

From 7155ec8beb27e95a2d51b40e5085ab8aca676a0b Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 03:07:51 +0800
Subject: [PATCH 33/70] Fix a bug that the exported projects are ordered
 differently in different `sbt millInitExportBuild` runs and on different OSs,
 causing `main.init.sbt.test` to fail on other OSs

---
 .../sbt/src/mill/main/sbt/SbtBuildGenMain.scala  |  3 +++
 .../config/sbt-multi-project-example/build.mill  | 16 ++++++++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index d4d9907f4a1..d49e235f207 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -125,12 +125,15 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
     import upickle.default.*
     val buildExport = read[BuildExport](buildExportPickled)
 
+    import scala.math.Ordering.Implicits.*
     // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
     val projectNodesByParentDirs: Map[Option[Seq[String]], View[Node[Project]]] =
       buildExport.projects.view
         .map(project =>
           Node(os.Path(project.projectDirectory).subRelativeTo(workspace).segments, project)
         )
+        // The projects are ordered differently in different `sbt millInitExportBuild` runs and on different OSs, which is strange.
+        .sortBy(_.dirs)
         .groupBy(node => {
           val dirs = node.dirs
           Option.when(dirs.nonEmpty)(dirs.dropRight(1))
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index 4807d5264e1..b65e2b7c1d0 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -37,12 +37,10 @@ object `package` extends RootModule with BaseModule {
 
   def artifactName = "sbt-multi-project-example"
 
-  object multi1 extends BaseModule {
+  object common extends BaseModule {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
-      Deps.`com.github.julien-truffaut:monocle-core`,
-      Deps.`com.github.julien-truffaut:monocle-macro`,
       Deps.`com.typesafe.akka:akka-stream`,
       Deps.`com.typesafe.scala-logging:scala-logging`,
       Deps.`com.typesafe:config`,
@@ -50,8 +48,6 @@ object `package` extends RootModule with BaseModule {
       Deps.`org.slf4j:jcl-over-slf4j`
     )
 
-    def moduleDeps = super.moduleDeps ++ Seq(build.common)
-
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
@@ -60,11 +56,12 @@ object `package` extends RootModule with BaseModule {
     }
   }
 
-  object multi2 extends BaseModule {
+  object multi1 extends BaseModule {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
-      Deps.`com.github.pureconfig:pureconfig`,
+      Deps.`com.github.julien-truffaut:monocle-core`,
+      Deps.`com.github.julien-truffaut:monocle-macro`,
       Deps.`com.typesafe.akka:akka-stream`,
       Deps.`com.typesafe.scala-logging:scala-logging`,
       Deps.`com.typesafe:config`,
@@ -82,10 +79,11 @@ object `package` extends RootModule with BaseModule {
     }
   }
 
-  object common extends BaseModule {
+  object multi2 extends BaseModule {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.github.pureconfig:pureconfig`,
       Deps.`com.typesafe.akka:akka-stream`,
       Deps.`com.typesafe.scala-logging:scala-logging`,
       Deps.`com.typesafe:config`,
@@ -93,6 +91,8 @@ object `package` extends RootModule with BaseModule {
       Deps.`org.slf4j:jcl-over-slf4j`
     )
 
+    def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
     object tests extends MavenTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++

From 3ef1bef6c24dd4fe441f9671d2901a2695d68c3c Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 16:57:50 +0800
Subject: [PATCH 34/70] Try fixing integration test timeout in the CI

---
 integration/feature/init/src/MillInitSbtTests.scala | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 14017277173..8076b4bb7b5 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -80,7 +80,7 @@ object MillInitScalaCsv136Tests extends BuildGenTestSuite {
 object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 10 KB
+    - 12 KB
     - originally sbt 1.0.2
      */
     val url =
@@ -157,7 +157,7 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
 object MillInitSbtCatsTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 2 MB
+    - 1.9 MB
     - sbt 1.10.7
     - MUnit
      */
@@ -177,9 +177,11 @@ object MillInitSbtCatsTests extends BuildGenTestSuite {
 
 // Converting child projects nested in a parent directory which is not a project is not supported yet.
 object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
+  // Commented out as it causes `java.util.concurrent.TimeoutException: Future timed out after [600000 milliseconds]` in the CI.
+  /*
   def tests: Tests = Tests {
     /*
-    - 5 MB
+    - 4.8 MB
     - sbt 1.10.5
      */
     val url = "https://github.com/playframework/playframework/archive/refs/tags/3.0.6.zip"
@@ -194,13 +196,14 @@ object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
       assert(compileResult.isSuccess)
     }
   }
+  */
 }
 
 // Scala.js and scala-native projects are not properly imported
 object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
-    - 0.5 MB
+    - 245 KB
     - sbt 1.10.1
      */
     val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"

From 1655bb934cd16ae5880e4c18fcfb4af5d4578784 Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 17:27:01 +0800
Subject: [PATCH 35/70] Fix a compiling error introduced in the previous commit

---
 integration/feature/init/src/MillInitSbtTests.scala | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 8076b4bb7b5..bea432a0b4a 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -177,9 +177,9 @@ object MillInitSbtCatsTests extends BuildGenTestSuite {
 
 // Converting child projects nested in a parent directory which is not a project is not supported yet.
 object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
-  // Commented out as it causes `java.util.concurrent.TimeoutException: Future timed out after [600000 milliseconds]` in the CI.
-  /*
   def tests: Tests = Tests {
+    // Commented out as it causes `java.util.concurrent.TimeoutException: Future timed out after [600000 milliseconds]` in the CI.
+    /*
     /*
     - 4.8 MB
     - sbt 1.10.5
@@ -195,8 +195,8 @@ object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
     }
+     */
   }
-  */
 }
 
 // Scala.js and scala-native projects are not properly imported

From 6b717b7423dd802a50bc25a2110fc6f1843d4d30 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 19:47:46 +0800
Subject: [PATCH 36/70] Try fixing more integration test failures on CI, both
 on Linux with JDK 11 and Windows with JDK 17

---
 .../feature/init/src/MillInitSbtTests.scala   | 21 +++++++---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 42 +++++++++++--------
 2 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index bea432a0b4a..4eb7f9ac838 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -36,13 +36,15 @@ object MillInitScalaCsv200Tests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 34 KB
-    - sbt 1.10.7
+    - originally sbt 1.10.0
      */
     val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/2.0.0.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      bumpSbtTo1107(workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
@@ -97,9 +99,12 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
 
-      // Submodules don't compile well, which seems to be due to incompatible bytecode versions in dependencies.
       val compileSubmodulesResult = eval("_.compile")
-      assert(!compileSubmodulesResult.isSuccess)
+      if (System.getProperty("java.version").split('.').head.toInt <= 11)
+        assert(compileSubmodulesResult.isSuccess)
+      else
+        // Submodules don't compile well with JDK 17 and 21, which seems to be due to incompatible bytecode versions in dependencies.
+        assert(!compileSubmodulesResult.isSuccess)
     }
   }
 }
@@ -110,13 +115,15 @@ object MillInitZioHttpTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 1.4 MB
-    - sbt 1.10.6
+    - originally sbt 1.10.0
      */
     val url = "https://github.com/zio/zio-http/archive/refs/tags/v3.0.1.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      bumpSbtTo1107(workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
@@ -135,7 +142,7 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 0.8 MB
-    - sbt 1.10.7
+    - sbt 1.9.7
      */
     val url = "https://github.com/scalaz/scalaz/archive/refs/tags/v7.3.8.zip"
 
@@ -204,13 +211,15 @@ object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 245 KB
-    - sbt 1.10.1
+    - originally sbt 1.10.1
      */
     val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"
 
     test - integrationTest(url) { tester =>
       import tester.*
 
+      bumpSbtTo1107(workspacePath)
+
       val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index d49e235f207..89e7bc64f5b 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -62,24 +62,32 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     println("converting sbt build")
 
-    val isWindows = Util.isWindows
-    val systemSbt = if (isWindows) "sbt.bat" else "sbt"
-
-    // resolve the sbt executable
-    // https://raw.githubusercontent.com/paulp/sbt-extras/master/sbt
-    val sbtExecutable = if (os.exists(workspace / "sbt"))
-      "./sbt"
-    else if (os.exists(workspace / "sbtx"))
-      "./sbtx"
-    else if (
+    def systemSbtExists(sbt: String) =
       // The return code is somehow 1 instead of 0.
-      os.call((systemSbt, "--help"), check = false).exitCode == 1
-    )
-      systemSbt
-    else
-      throw new RuntimeException(
-        s"No sbt executable (`./sbt`, `./sbtx`, or system-wide `$systemSbt`) found"
-      )
+      os.call((sbt, "--help"), check = false).exitCode == 1
+
+    val isWindows = Util.isWindows
+    val sbtExecutable = if (isWindows) {
+      val systemSbt = "sbt.bat"
+      if (systemSbtExists(systemSbt))
+        systemSbt
+      else
+        throw new RuntimeException(s"No system-wide `$systemSbt` found")
+    } else {
+      val systemSbt = "sbt"
+      // resolve the sbt executable
+      // https://raw.githubusercontent.com/paulp/sbt-extras/master/sbt
+      if (os.exists(workspace / "sbt"))
+        "./sbt"
+      else if (os.exists(workspace / "sbtx"))
+        "./sbtx"
+      else if (systemSbtExists(systemSbt))
+        systemSbt
+      else
+        throw new RuntimeException(
+          s"No sbt executable (`./sbt`, `./sbtx`, or system-wide `$systemSbt`) found"
+        )
+    }
 
     println("Running the added `millInitExportBuild` sbt task to export the build")
 

From 018cd53f7fef453d1560dc502f2d365c5e8bfa4a Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 21:07:35 +0800
Subject: [PATCH 37/70] Fix the failing example tests added in commit
 3d2fafed6a2cdcbce2f8c6cc79a54e3c63e68e66

---
 .../migrating/1-sbt-complete/build.mill         | 17 +++++++----------
 .../migrating/2-sbt-incomplete/build.mill       | 16 +++-------------
 2 files changed, 10 insertions(+), 23 deletions(-)

diff --git a/example/scalalib/migrating/1-sbt-complete/build.mill b/example/scalalib/migrating/1-sbt-complete/build.mill
index 5eb364e717a..590ce14912b 100644
--- a/example/scalalib/migrating/1-sbt-complete/build.mill
+++ b/example/scalalib/migrating/1-sbt-complete/build.mill
@@ -1,12 +1,12 @@
 /** Usage
 
- > rm build.mill # remove any existing build file
+> rm build.mill # remove any existing build file
 
- > git init .
- > git remote add -f origin https://github.com/scalacenter/library-example.git
- > git checkout v1.0.1
+> git init .
+> git remote add -f origin https://github.com/scalacenter/library-example.git
+> git checkout v1.0.1
 
- > ./mill init
+> ./mill init
 converting module library-example
 Dependency Dependency(com.lightbend.paradox,paradox-theme-generic,false,0.4.4,Some(paradox-theme)) with an unknown configuration "paradox-theme" is dropped.
 Dependency Dependency(com.lightbend.paradox,paradox-theme-generic,false,0.4.4,Some(paradox-theme)) with an unknown configuration "paradox-theme" is dropped.
@@ -16,11 +16,8 @@ writing Mill build file to build.mill
 converted sbt build to Mill
 formatting Mill build files
 Formatting 1 Scala sources
-parsed config (v3.8.4): /var/folders/xh/9t7mxl615nv8627_v54lc9ph0000gn/T/3390681381000847719.tmp
 init completed, run "mill resolve _" to list available tasks
 
- > ./mill compile
- [46/46] compile
- [46] [info] compiling 1 Scala source to /.../libsam/out/compile.dest/classes ...
- [46] [info] done compiling
+> ./mill compile
+done compiling
 */
diff --git a/example/scalalib/migrating/2-sbt-incomplete/build.mill b/example/scalalib/migrating/2-sbt-incomplete/build.mill
index 1508ddbdd3b..69e4a9bec2e 100644
--- a/example/scalalib/migrating/2-sbt-incomplete/build.mill
+++ b/example/scalalib/migrating/2-sbt-incomplete/build.mill
@@ -9,12 +9,6 @@
 > ./mill init
 converting sbt build
 Running the added `millInitExportBuild` sbt task to export the build
-[info] welcome to sbt 1.10.0 (Eclipse Adoptium Java 17.0.14)
-[info] loading settings for project test-build from plugins.sbt,mill-init.sbt ...
-[info] loading project definition from /.../project
-[info] loading settings for project test from build.sbt,doctest.sbt ...
-[info] set current project to scala-csv (in build file:/.../)
-[success] Total time: 0 s, completed Feb 19, 2025, 1:42:45 AM
 converting module scala-csv
 generated 1 Mill build file(s)
 removing existing Mill build files
@@ -22,14 +16,10 @@ writing Mill build file to build.mill
 converted sbt build to Mill
 formatting Mill build files
 Formatting 1 Scala sources
-parsed config (v3.8.4): /var/folders/xh/9t7mxl615nv8627_v54lc9ph0000gn/T/17040603558958375710.tmp
 init completed, run "mill resolve _" to list available tasks
 
 > ./mill compile # You will have to further configure the `CrossScalaModule` for different Scala versions
- [46/46] compile
- [46] [info] compiling 7 Scala sources and 3 Java sources to /.../out/compile.dest/classes ...
- [46] [error] /.../src/main/scala/com/github/tototoshi/csv/CSVReader.scala:24:115: not found: type CSVReaderCompat
- [46] [error] class CSVReader protected (private val lineReader: LineReader)(implicit format: CSVFormat) extends Closeable with CSVReaderCompat {
- [46] [error]                                                                                                                   ^
- [46] [error] one error found
+error: class CSVReader protected (private val lineReader: LineReader)(implicit format: CSVFormat) extends Closeable with CSVReaderCompat {
+error:                                                                                                                   ^
+error: one error found
 */

From 4112c6fc64c311337ffda3eb530a8e25b1374fc9 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 21:15:19 +0800
Subject: [PATCH 38/70] Run `./mill
 mill.scalalib.scalafmt.ScalafmtModule/reformatAll` since `lint-autofix` fails
 on CI

---
 .../init/buildgen/src/mill/main/buildgen/BuildGenBase.scala | 3 ++-
 main/init/buildgen/src/mill/main/buildgen/ir.scala          | 6 +++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 50a4c84dad2..3b1bed816bd 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -35,7 +35,8 @@ trait BuildGenBase[M, D, I] {
       val isNested = build.dirs.nonEmpty
       build.copy(value =
         BuildObject(
-          imports = BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size, extraImports),
+          imports =
+            BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size, extraImports),
           companions =
             shared.depsObject.fold(SortedMap.empty[String, BuildObject.Constants])(name =>
               SortedMap((name, SortedMap(inner.scopedDeps.namedIvyDeps.toSeq*)))
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index c41c272ec5b..c4852b44b30 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -85,7 +85,7 @@ case class IrBuild(
     dirs: Seq[String],
     repositories: Seq[String],
     javacOptions: Seq[String],
-    scalaVersion : Option[String],
+    scalaVersion: Option[String],
     scalacOptions: Option[Seq[String]],
     projectName: String,
     pomSettings: IrPom,
@@ -117,8 +117,8 @@ case class IrScopedDeps(
 
 case class IrBaseInfo(
     javacOptions: Seq[String] = Nil,
-    scalaVersion : Option[String] = None,
-    scalacOptions : Option[Seq[String]] = None,
+    scalaVersion: Option[String] = None,
+    scalacOptions: Option[Seq[String]] = None,
     repositories: Seq[String] = Nil,
     noPom: Boolean = true,
     publishVersion: String = "",

From 40cdaa33636a0d019082768e04e560c586b9e473 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 21:32:09 +0800
Subject: [PATCH 39/70] Add one more exception in docs from the integration
 test failures fixed in commit 6b717b7423dd802a50bc25a2110fc6f1843d4d30

---
 website/docs/modules/ROOT/pages/migrating/sbt.adoc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/website/docs/modules/ROOT/pages/migrating/sbt.adoc b/website/docs/modules/ROOT/pages/migrating/sbt.adoc
index 825b0710296..bf7a60abe0e 100644
--- a/website/docs/modules/ROOT/pages/migrating/sbt.adoc
+++ b/website/docs/modules/ROOT/pages/migrating/sbt.adoc
@@ -110,8 +110,9 @@ or xref:extending/thirdparty-plugins.adoc[third party] plugins
 == FAQ
 
 How to fix errors such as
-`java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release` and
-`java.io.IOError: java.lang.RuntimeException: /packages cannot be represented as URI`
+`java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release`,
+`java.io.IOError: java.lang.RuntimeException: /packages cannot be represented as URI`,
+and `java.lang.RuntimeException: java.lang.reflect.InvocationTargetException`
 thrown by the sbt command invoked by `mill init`?
 
 Update the project's sbt version to the latest or our tested version v1.10.7, and try again.

From 3cfb3aa04595405177e79ff26f127b2e59144c13 Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 23:07:11 +0800
Subject: [PATCH 40/70] Add `setup-sbt` in `autofix.ci` too as it fails without
 it

---
 .github/workflows/autofix.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/autofix.yml b/.github/workflows/autofix.yml
index ce356a24ebc..fff08f9d91e 100644
--- a/.github/workflows/autofix.yml
+++ b/.github/workflows/autofix.yml
@@ -7,6 +7,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: sbt/setup-sbt@v1
+
       - run: |
           ./mill __.fix + mill.javalib.palantirformat.PalantirFormatModule/ + mill.scalalib.scalafmt.ScalafmtModule/ + mill.kotlinlib.ktlint.KtlintModule/
           ./mill --meta-level 1 mill.scalalib.scalafmt.ScalafmtModule/

From 7ed2c3a1a7dbf32aab392ab6d66f2e91617f05d3 Mon Sep 17 00:00:00 2001
From: Shreck Ye <ShreckYe@gmail.com>
Date: Thu, 20 Feb 2025 23:20:16 +0800
Subject: [PATCH 41/70] Fix the merge

---
 main/src/mill/main/MainModule.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/src/mill/main/MainModule.scala b/main/src/mill/main/MainModule.scala
index ba8f14036be..d08d5f20600 100644
--- a/main/src/mill/main/MainModule.scala
+++ b/main/src/mill/main/MainModule.scala
@@ -279,7 +279,7 @@ trait MainModule extends BaseModule {
             SelectMode.Separated
           )
         else if (os.exists(os.pwd / "build.sbt"))
-          evaluator.resolveEvaluate(
+          evaluator.evaluate(
             Seq("mill.init.InitSbtModule/init") ++ args,
             SelectMode.Separated
           )

From ee2837700dd7f577ddb308ec010e0407ac6e98d1 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sat, 22 Feb 2025 16:21:49 +0800
Subject: [PATCH 42/70] Support converting child projects nested in a parent
 directory which is not a project

- An extra `OM` abstract type is added in `BuildGenBase`.
  - `OM = M` in the Maven and Gradle implementations.
  - `OM = Option[Project]` in `SbtBuildGenMain`.
- A `merge` algorithm is added to create `Tree[Node[Option[T]]]`s.
- Improve code in the Maven and Gradle implementations BTW.
- Add a nested module in `main/init/sbt/test/resources/sbt-multi-project-example/build.sbt` to test the change and fix revealed bugs.
---
 .../src/mill/main/buildgen/BuildGenBase.scala | 82 ++++++++++++-------
 .../src/mill/main/buildgen/BuildGenUtil.scala |  9 +-
 .../mill/main/buildgen/OptionNodeTree.scala   | 33 ++++++++
 .../buildgen/src/mill/main/buildgen/ir.scala  | 22 +++++
 .../mill/main/gradle/GradleBuildGenMain.scala | 12 ++-
 .../mill/main/maven/MavenBuildGenMain.scala   |  6 +-
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 35 ++++----
 .../sbt-multi-project-example/build.mill      |  5 ++
 .../nested/nested/package.mill                | 58 +++++++++++++
 .../nested/package.mill                       |  5 ++
 .../sbt-multi-project-example/build.sbt       |  3 +
 11 files changed, 208 insertions(+), 62 deletions(-)
 create mode 100644 main/init/buildgen/src/mill/main/buildgen/OptionNodeTree.scala
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
 create mode 100644 main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/package.mill

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 3b1bed816bd..5feaf83e372 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -2,8 +2,13 @@ package mill.main.buildgen
 
 import mill.main.buildgen.BuildGenUtil.{buildPackages, compactBuildTree, writeBuildObject}
 
-import scala.collection.immutable.SortedMap
+import scala.collection.immutable.{SortedMap, SortedSet}
 
+/*
+TODO Can we just convert all generic type parameters to abstract type members?
+ See https://stackoverflow.com/a/1154727/5082913.
+ I think abstract type members are preferred in this case.
+ */
 trait BuildGenBase[M, D, I] {
   type C
   def convertWriteOut(cfg: C, shared: BuildGenUtil.BasicConfig, input: I): Unit = {
@@ -11,49 +16,63 @@ trait BuildGenBase[M, D, I] {
     writeBuildObject(if (shared.merge.value) compactBuildTree(output) else output)
   }
 
-  def getProjectTree(input: I): Tree[Node[M]]
+  /**
+   * A possibly optional module model which might be a parent directory of an actual module without its own sources.
+   */
+  type OM
+  extension (om: OM) def toOption(): Option[M]
+
+  def getModuleTree(input: I): Tree[Node[OM]]
 
   def convert(
       input: I,
       cfg: C,
       shared: BuildGenUtil.BasicConfig
   ): Tree[Node[BuildObject]] = {
-    val projectTree = getProjectTree(input)
+    val moduleTree = getModuleTree(input)
+    val moduleOptionTree = moduleTree.map(node => node.copy(value = node.value.toOption()))
 
     // for resolving moduleDeps
-    val packages = buildPackages(projectTree)(getPackage)
+    val packages = buildPackages(
+      moduleOptionTree.nodes().flatMap(node => node.value.map(m => node.copy(value = m)))
+    )(getPackage)
 
     val baseInfo =
       shared.baseModule.fold(IrBaseInfo()) { getBaseInfo(input, cfg, _, packages.size) }
 
-    projectTree.map { build =>
-      val name = getArtifactId(build.value)
-      println(s"converting module $name")
-
-      val inner = extractIrBuild(cfg, baseInfo, build, packages)
-
-      val isNested = build.dirs.nonEmpty
-      build.copy(value =
-        BuildObject(
-          imports =
-            BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size, extraImports),
-          companions =
-            shared.depsObject.fold(SortedMap.empty[String, BuildObject.Constants])(name =>
-              SortedMap((name, SortedMap(inner.scopedDeps.namedIvyDeps.toSeq*)))
-            ),
-          supertypes = getSuperTypes(cfg, baseInfo, build),
-          inner = BuildGenUtil.renderIrBuild(inner),
-          outer =
-            if (isNested || baseInfo.moduleTypedef == null) ""
-            else BuildGenUtil.renderIrTrait(baseInfo.moduleTypedef)
-        )
+    moduleOptionTree.map(optionalBuild =>
+      optionalBuild.copy(value =
+        optionalBuild.value.fold(
+          BuildObject(SortedSet("mill._"), SortedMap.empty, Seq("RootModule", "Module"), "", "")
+        )(moduleModel => {
+          val name = getArtifactId(moduleModel)
+          println(s"converting module $name")
+
+          val build = optionalBuild.copy(value = moduleModel)
+          val inner = extractIrBuild(cfg, baseInfo, build, packages)
+
+          val isNested = optionalBuild.dirs.nonEmpty
+          BuildObject(
+            imports =
+              BuildGenUtil.renderImports(shared.baseModule, isNested, packages.size, extraImports),
+            companions =
+              shared.depsObject.fold(SortedMap.empty[String, BuildObject.Constants])(name =>
+                SortedMap((name, SortedMap(inner.scopedDeps.namedIvyDeps.toSeq*)))
+              ),
+            supertypes = getSupertypes(cfg, baseInfo, build),
+            inner = BuildGenUtil.renderIrBuild(inner),
+            outer =
+              if (isNested || baseInfo.moduleTypedef == null) ""
+              else BuildGenUtil.renderIrTrait(baseInfo.moduleTypedef)
+          )
+        })
       )
-    }
+    )
   }
 
   def extraImports: Seq[String]
 
-  def getSuperTypes(cfg: C, baseInfo: IrBaseInfo, build: Node[M]): Seq[String]
+  def getSupertypes(cfg: C, baseInfo: IrBaseInfo, build: Node[M]): Seq[String]
 
   def getBaseInfo(
       input: I,
@@ -62,9 +81,9 @@ trait BuildGenBase[M, D, I] {
       packagesSize: Int
   ): IrBaseInfo
 
-  def getPackage(model: M): (String, String, String)
+  def getPackage(moduleModel: M): (String, String, String)
 
-  def getArtifactId(model: M): String
+  def getArtifactId(moduleModel: M): String
 
   def extractIrBuild(
       cfg: C,
@@ -75,7 +94,8 @@ trait BuildGenBase[M, D, I] {
 }
 
 object BuildGenBase {
-  trait BaseInfoFromSubproject[M, D] extends BuildGenBase[M, D, Tree[Node[M]]] {
-    override def getProjectTree(input: Tree[Node[M]]): Tree[Node[M]] = input
+  trait MavenAndGradle[M, D] extends BuildGenBase[M, D, Tree[Node[M]]] {
+    override def getModuleTree(input: Tree[Node[M]]): Tree[Node[M]] = input
+    override type OM = M
   }
 }
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index 1cc9279ab7b..ccc8dbce456 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -1,14 +1,15 @@
 package mill.main.buildgen
 
+import geny.Generator
 import mainargs.{Flag, arg}
-import mill.constants.OutFiles
-import mill.main.buildgen.BuildObject.Companions
 import mill.constants.CodeGenConstants.{
   buildFileExtensions,
   nestedBuildFileNames,
   rootBuildFileNames,
   rootModuleAlias
 }
+import mill.constants.OutFiles
+import mill.main.buildgen.BuildObject.Companions
 import mill.runner.FileImportGraph.backtickWrap
 
 import scala.collection.immutable.SortedSet
@@ -160,9 +161,9 @@ object BuildGenUtil {
   def buildPackage(dirs: Seq[String]): String =
     (rootModuleAlias +: dirs).iterator.map(backtickWrap).mkString(".")
 
-  def buildPackages[Module, Key](input: Tree[Node[Module]])(key: Module => Key)
+  def buildPackages[Module, Key](input: Generator[Node[Module]])(key: Module => Key)
       : Map[Key, String] =
-    input.nodes()
+    input
       .map(node => (key(node.value), buildPackage(node.dirs)))
       .toSeq
       .toMap
diff --git a/main/init/buildgen/src/mill/main/buildgen/OptionNodeTree.scala b/main/init/buildgen/src/mill/main/buildgen/OptionNodeTree.scala
new file mode 100644
index 00000000000..c136d5b3bfb
--- /dev/null
+++ b/main/init/buildgen/src/mill/main/buildgen/OptionNodeTree.scala
@@ -0,0 +1,33 @@
+package mill.main.buildgen
+
+def toTree[T](prefixDirs: Seq[String], dirs: List[String], node: Node[T]): Tree[Node[Option[T]]] =
+  dirs match
+    case Nil => Tree(node.copy(value = Some(node.value)))
+    case dir :: nextDirs =>
+      Tree(Node(prefixDirs, None), Seq(toTree(prefixDirs :+ dir, nextDirs, node)))
+
+def merge[T](
+    tree: Tree[Node[Option[T]]],
+    prefixDirs: Seq[String],
+    dirs: List[String],
+    node: Node[T]
+): Tree[Node[Option[T]]] =
+  dirs match
+    case Nil => tree.copy(node =
+        tree.node.value.fold(node.copy(value = Some(node.value)))(existingProject =>
+          throw IllegalArgumentException(
+            s"Project at duplicate locations: $existingProject and $node"
+          )
+        )
+      )
+    case dir :: nextDirs =>
+      tree.copy(children = {
+        def nextPrefixDirs = prefixDirs :+ dir
+        tree.children.iterator.zipWithIndex.find(_._1.node.dirs.last == dir) match
+          case Some((childTree, index)) =>
+            tree.children.updated(index, merge(childTree, nextPrefixDirs, nextDirs, node))
+          case None => tree.children :+ toTree(nextPrefixDirs, nextDirs, node)
+      })
+
+def merge[T](tree: Tree[Node[Option[T]]], node: Node[T]): Tree[Node[Option[T]]] =
+  merge(tree, Seq.empty, node.dirs.toList, node)
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index c4852b44b30..7fe838f1327 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -97,6 +97,28 @@ case class IrBuild(
     publishProperties: Seq[(String, String)]
 )
 
+object IrBuild {
+  // TODO not used
+  def empty(dirs: Seq[String]) = IrBuild(
+    IrScopedDeps(),
+    null,
+    false,
+    dirs,
+    Seq.empty,
+    Seq.empty,
+    None,
+    None,
+    dirs.last,
+    null,
+    null,
+    null,
+    null,
+    Seq.empty,
+    Seq.empty,
+    Seq.empty
+  )
+}
+
 case class IrScopedDeps(
     // TODO The type is `Seq` and this is deduplicated and sorted in `BuildGenUtil`. Make the type `SortedMap` here for consistency?
     namedIvyDeps: Seq[(String, String)] = Nil,
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index bedce60427e..64ce64ac682 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -40,7 +40,7 @@ import scala.jdk.CollectionConverters.*
  *  - non-Java sources
  */
 @mill.api.internal
-object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectModel, JavaModel.Dep] {
+object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, JavaModel.Dep] {
   type C = Config
 
   def main(args: Array[String]): Unit = {
@@ -103,6 +103,10 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
     file
   }
 
+  extension (om: ProjectModel) override def toOption(): Option[ProjectModel] =
+    // TODO consider filtering out projects without the `java` plugin applied
+    Some(om)
+
   def getBaseInfo(
       input: Tree[Node[ProjectModel]],
       cfg: Config,
@@ -197,11 +201,11 @@ object GradleBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[ProjectMod
     (project.group(), project.name(), project.version())
   }
 
-  def getArtifactId(model: ProjectModel): String = model.name()
+  def getArtifactId(project: ProjectModel): String = project.name()
 
-  def getMillSourcePath(model: ProjectModel): Path = os.Path(model.directory())
+  def getMillSourcePath(project: ProjectModel): Path = os.Path(project.directory())
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] =
+  def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] =
     Seq("RootModule") ++
       Option.when(null != build.value.maven().pom() && baseInfo.noPom) { "PublishModule" } ++
       Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index d7b6b905039..89af57b1b7a 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -36,7 +36,7 @@ import scala.jdk.CollectionConverters.*
  *  - build profiles
  */
 @mill.api.internal
-object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Dependency] {
+object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency] {
   type C = Config
 
   def main(args: Array[String]): Unit = {
@@ -59,6 +59,8 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
     println("converted Maven build to Mill")
   }
 
+  extension (om: Model) override def toOption(): Option[Model] = Some(om)
+
   def getBaseInfo(
       input: Tree[Node[Model]],
       cfg: Config,
@@ -144,7 +146,7 @@ object MavenBuildGenMain extends BuildGenBase.BaseInfoFromSubproject[Model, Depe
 
   def getMillSourcePath(model: Model): Path = os.Path(model.getProjectDirectory)
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] =
+  def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] =
     Seq("RootModule") ++
       cfg.shared.basicConfig.baseModule.fold(getModuleSupertypes(cfg))(Seq(_))
 
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 89e7bc64f5b..0acfc9df432 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -7,8 +7,8 @@ import mill.main.buildgen.BuildGenUtil.*
 import mill.main.buildgen.IrDependencyType.*
 import os.Path
 
+import scala.collection.MapView
 import scala.collection.immutable.SortedSet
-import scala.collection.{MapView, View}
 
 /**
  * Converts an sbt build to Mill by generating Mill build file(s).
@@ -49,8 +49,10 @@ import scala.collection.{MapView, View}
  *  - cross builds
  */
 @mill.api.internal
-object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[Node[Project]])] {
+object SbtBuildGenMain
+    extends BuildGenBase[Project, String, (BuildInfo, Tree[Node[Option[Project]]])] {
   type C = Config
+  override type OM = Option[Project]
 
   def main(args: Array[String]): Unit = {
     val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
@@ -135,30 +137,17 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
     import scala.math.Ordering.Implicits.*
     // Types have to be specified explicitly here for the code to be resolved correctly in IDEA.
-    val projectNodesByParentDirs: Map[Option[Seq[String]], View[Node[Project]]] =
+    val projectNodes =
       buildExport.projects.view
         .map(project =>
           Node(os.Path(project.projectDirectory).subRelativeTo(workspace).segments, project)
         )
         // The projects are ordered differently in different `sbt millInitExportBuild` runs and on different OSs, which is strange.
         .sortBy(_.dirs)
-        .groupBy(node => {
-          val dirs = node.dirs
-          Option.when(dirs.nonEmpty)(dirs.dropRight(1))
-        })
 
-    /*
-    TODO This does not support converting child projects nested in a parent directory which is not a project yet.
-     Supporting this may involve refactoring `Node[Project]` into `Node[Option[Project]]`
-     or adding a subproject as a direct child with its ancestor directory project (I am not sure whether this works).
-     */
-    val input = Tree.from(projectNodesByParentDirs(None).head) { node =>
-      val dirs = node.dirs
-      val children = projectNodesByParentDirs.getOrElse(Some(dirs), Seq.empty)
-      (node, children)
-    }
+    val projectNodeTree = projectNodes.foldLeft(Tree(Node(Seq.empty, None)))(merge)
 
-    convertWriteOut(cfg, cfg.shared, (buildExport.defaultBuildInfo, input))
+    convertWriteOut(cfg, cfg.shared, (buildExport.defaultBuildInfo, projectNodeTree))
 
     println("converted sbt build to Mill")
   }
@@ -199,13 +188,17 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
       suffix = ".sbt"
     )
 
-  override def getProjectTree(input: (BuildInfo, Tree[Node[Project]])): Tree[Node[Project]] =
+  extension (om: Option[Project]) override def toOption(): Option[Project] = om
+
+  override def getModuleTree(
+      input: (BuildInfo, Tree[Node[Option[Project]]])
+  ): Tree[Node[Option[Project]]] =
     input._2
 
   def sbtSupertypes = Seq("SbtModule", "PublishModule") // always publish
 
   def getBaseInfo(
-      input: (BuildInfo, Tree[Node[Project]]),
+      input: (BuildInfo, Tree[Node[Option[Project]]]),
       cfg: Config,
       baseModule: String,
       packagesSize: Int
@@ -292,7 +285,7 @@ object SbtBuildGenMain extends BuildGenBase[Project, String, (BuildInfo, Tree[No
 
   def getMillSourcePath(project: Project): Path = os.Path(project.projectDirectory)
 
-  def getSuperTypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Project]): Seq[String] =
+  override def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Project]): Seq[String] =
     Seq("RootModule") ++ getModuleSupertypes(cfg)
 
   def groupArtifactVersion(dep: Dependency): (String, String, String) =
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index b65e2b7c1d0..d3568bfed01 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -100,6 +100,11 @@ object `package` extends RootModule with BaseModule {
 
     }
   }
+
+  object nested extends Module {
+
+    object nested extends BaseModule {}
+  }
 }
 
 trait BaseModule extends SbtModule with PublishModule {
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
new file mode 100644
index 00000000000..e4c9672c52f
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
@@ -0,0 +1,58 @@
+package build.nested.nested
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object `package` extends RootModule with SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def pomSettings = PomSettings(
+    "This is an sbt sample project for testing Mill's init command.",
+    "com.pbassiner",
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+}
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/package.mill
new file mode 100644
index 00000000000..681780798ae
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/package.mill
@@ -0,0 +1,5 @@
+package build.nested
+
+import mill._
+
+object `package` extends RootModule with Module {}
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index 7ac330b18b3..64f33161bda 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -56,6 +56,9 @@ lazy val multi2 = project
     common
   )
 
+lazy val nested = project
+  .in(file("nested/nested"))
+
 // DEPENDENCIES
 
 lazy val dependencies =

From 88c31b18e667274563ca953ef7442d877ef2a129 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sat, 22 Feb 2025 21:00:19 +0800
Subject: [PATCH 43/70] Run more `compile` and `test` tasks in the submodules
 of part of the generated builds in the integration tests

Some common code is extracted and added in `IntegrationTesterExt.scala`.
---
 .../init/src/IntegrationTesterExt.scala       |  75 +++++++++
 .../feature/init/src/MillInitSbtTests.scala   | 148 ++++++++++--------
 2 files changed, 157 insertions(+), 66 deletions(-)
 create mode 100644 integration/feature/init/src/IntegrationTesterExt.scala

diff --git a/integration/feature/init/src/IntegrationTesterExt.scala b/integration/feature/init/src/IntegrationTesterExt.scala
new file mode 100644
index 00000000000..e87f6ba043a
--- /dev/null
+++ b/integration/feature/init/src/IntegrationTesterExt.scala
@@ -0,0 +1,75 @@
+package mill.integration
+
+import mill.testkit.IntegrationTester
+import utest.*
+
+val defaultInitCommand =
+  Seq("init", "--base-module", "BaseModule", "--deps-object", "Deps", "--merge")
+
+case class SplitResolvedTasks(successful: Seq[String], failed: Seq[String]) {
+  val all = (successful ++ failed).toSet
+}
+
+extension (tester: IntegrationTester)
+  /**
+   * @param expectedCompileTasks [[ None ]] to denote that the `resolve __.compile` task fails
+   * @param expectedTestTasks [[ None ]] to denote that the `resolve __.test` task fails
+   * @return
+   */
+  def testMillInit(
+      initCommand: Seq[String] = defaultInitCommand,
+      expectedInitResult: Boolean = true,
+      // expectedCompileResult: Boolean,
+      expectedCompileTasks: Option[SplitResolvedTasks],
+      expectedTestTasks: Option[SplitResolvedTasks]
+  ) = {
+    import tester.*
+
+    val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+    assert(initResult.isSuccess == expectedInitResult)
+
+    /*
+    val compileResult = eval("compile")
+    assert(compileResult.isSuccess == expectedCompileResult)
+     */
+
+    def testAllResolvedTasks(taskName: String, expected: Option[SplitResolvedTasks]) = {
+      val resolveAllTasksResult = eval(("resolve", s"__.$taskName"))
+      expected.fold(
+        assert(!resolveAllTasksResult.isSuccess)
+      )(expected => {
+        assert(resolveAllTasksResult.isSuccess)
+        val resolvedAllTasks =  resolveAllTasksResult.out.split('\n').toSet
+        Predef.assert(resolvedAllTasks == expected.all, "resolved tasks: " + resolvedAllTasks)
+
+        for (task <- expected.successful)
+          Predef.assert(eval(task).isSuccess, s"task $task failed")
+
+        for (task <- expected.failed)
+          Predef.assert(!eval(task).isSuccess, s"task $task succeeded")
+      })
+    }
+
+    testAllResolvedTasks("compile", expectedCompileTasks)
+    testAllResolvedTasks("test", expectedTestTasks)
+  }
+
+extension (module: String) {
+  def compileTask: String =
+    s"$module.compile"
+  private def testModuleOrTask: String =
+    s"$module.test"
+  def testTask: String =
+    testModuleOrTask
+  def testModule: String =
+    testModuleOrTask
+  def testCompileTask: String =
+    testModule.compileTask
+  def testTestTask: String =
+    testModule.testTask
+  def allCompileTasks: Seq[String] =
+    Seq(compileTask, testCompileTask)
+  // TODO This seems not needed.
+  def allTestTasks: Seq[String] =
+    Seq(testTask, testTestTask)
+}
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 4eb7f9ac838..c9bb1e4bd31 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -1,14 +1,11 @@
 package mill.integration
 
-import mill.integration.MillInitSbtTests.{bumpSbtTo1107, initCommand}
+import mill.integration.testMillInit
 import utest.*
 
-object MillInitSbtTests {
-  val initCommand = ("init", "--base-module", "BaseModule", "--deps-object", "Deps", "--merge")
-  def bumpSbtTo1107(workspacePath: os.Path) =
-    // bump sbt version to resolve compatibility issues with lower sbt versions and higher JDK versions
-    os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
-}
+def bumpSbtTo1107(workspacePath: os.Path) =
+  // bump sbt version to resolve compatibility issues with lower sbt versions and higher JDK versions
+  os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
 
 // relatively small libraries
 
@@ -20,15 +17,12 @@ object MillInitLibraryExampleTests extends BuildGenTestSuite {
      */
     val url = "https://github.com/scalacenter/library-example/archive/refs/tags/v1.0.1.zip"
 
-    test - integrationTest(url) { tester =>
-      import tester.*
-
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
-    }
+    test - integrationTest(url)(
+      _.testMillInit(
+        expectedCompileTasks = Some(SplitResolvedTasks(Seq("compile"), Seq())),
+        expectedTestTasks = None // scalaprops not supported in `TestModule`
+      )
+    )
   }
 }
 
@@ -41,16 +35,13 @@ object MillInitScalaCsv200Tests extends BuildGenTestSuite {
     val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/2.0.0.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
+      bumpSbtTo1107(tester.workspacePath)
 
-      bumpSbtTo1107(workspacePath)
-
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
       // Cross builds are not supported yet.
-      assert(!compileResult.isSuccess)
+      tester.testMillInit(
+        expectedCompileTasks = Some(SplitResolvedTasks(Seq(), Seq("compile", "test.compile"))),
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test" /*, "test.test"*/ )))
+      )
     }
   }
 }
@@ -64,16 +55,18 @@ object MillInitScalaCsv136Tests extends BuildGenTestSuite {
     val url = "https://github.com/tototoshi/scala-csv/archive/refs/tags/1.3.6.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
-
-      bumpSbtTo1107(workspacePath)
-
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
-      // It works here, but scala 2.11 with JDK 6 seems not supported when run with JDK 17 in shell.
-      assert(compileResult.isSuccess)
+      bumpSbtTo1107(tester.workspacePath)
+
+      tester.testMillInit(
+        expectedCompileTasks = Some(SplitResolvedTasks(
+          // It works here, but scala 2.11 with JDK 6 seems not supported when run with JDK 17 in shell.
+          Seq("compile"),
+          // `Not a Java dependency: Dep(Dependency(com.storm-enroute:scalameter, 0.8.2, Configuration(), Set(), Publication(, Type(), Extension(), Classifier()), false, true),Binary(false),false)`
+          // probably due to inheriting `MavenTests` instead of `SbtTests`
+          Seq("test.compile")
+        )),
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test" /*, "test.test"*/ )))
+      )
     }
   }
 }
@@ -89,22 +82,28 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
       "https://github.com/pbassiner/sbt-multi-project-example/archive/152b31df9837115b183576b0080628b43c505389.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
-
-      bumpSbtTo1107(workspacePath)
-
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
-
-      val compileSubmodulesResult = eval("_.compile")
-      if (System.getProperty("java.version").split('.').head.toInt <= 11)
-        assert(compileSubmodulesResult.isSuccess)
-      else
-        // Submodules don't compile well with JDK 17 and 21, which seems to be due to incompatible bytecode versions in dependencies.
-        assert(!compileSubmodulesResult.isSuccess)
+      bumpSbtTo1107(tester.workspacePath)
+
+      val submodules = Seq("common", "multi1", "multi2")
+
+      tester.testMillInit(
+        expectedCompileTasks =
+          Some(if (System.getProperty("java.version").split('.').head.toInt <= 11)
+            SplitResolvedTasks(
+              Seq("compile") ++ submodules.map(_.compileTask),
+              // probably due to inheriting `MavenTests` instead of `SbtTests`
+              submodules.map(_.testCompileTask)
+            )
+          else {
+            // Submodules don't compile well with JDK 17 and 21, which seems to be due to incompatible bytecode versions in dependencies.
+            val succeededSubmoduleCompileTasks = Seq("common.compile", "multi2.compile")
+            SplitResolvedTasks(
+              Seq("compile") ++ succeededSubmoduleCompileTasks,
+              (submodules.flatMap(_.allCompileTasks).toSet -- succeededSubmoduleCompileTasks).toSeq
+            )
+          }),
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), submodules.map(_.testTask)))
+      )
     }
   }
 }
@@ -120,19 +119,32 @@ object MillInitZioHttpTests extends BuildGenTestSuite {
     val url = "https://github.com/zio/zio-http/archive/refs/tags/v3.0.1.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
-
-      bumpSbtTo1107(workspacePath)
-
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
-
-      val compileSubmodulesResult = eval("_.compile")
+      bumpSbtTo1107(tester.workspacePath)
+
+      val submodules = Seq(
+        "sbt-zio-http-grpc-tests",
+        "sbt-zio-http-grpc",
+        "zio-http-benchmarks.compile",
+        "zio-http-cli",
+        "zio-http-docs",
+        "zio-http-example",
+        "zio-http-gen",
+        "zio-http-htmx",
+        "zio-http-testkit",
+        "zio-http-tools",
+        "zio-http.js",
+        "zio-http.jvm"
+      )
+
+      // TODO
+      /*
+      // probably due to inheriting `MavenTests` instead of `SbtTests`
       // Some dependencies with currently unsupported `CrossVersion` `For3Use2_13` are not imported properly
-      assert(!compileSubmodulesResult.isSuccess)
+      tester.testMillInit(
+        expectedCompileTasks = Some(SplitResolvedTasks(Seq("compile"), submodules.flatMap(_.allCompileTasks))),
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), submodules.flatMap(_.allTestTasks)))
+      )
+       */
     }
   }
 }
@@ -151,11 +163,15 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
 
       os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
 
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
       assert(compileResult.isSuccess)
+
+      // TODO
+      val resolveCompilesResult = eval(("resolve", "__.compile"))
+      println("Resolve result: " + resolveCompilesResult.out)
     }
   }
 }
@@ -173,7 +189,7 @@ object MillInitSbtCatsTests extends BuildGenTestSuite {
     test - integrationTest(url) { tester =>
       import tester.*
 
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
@@ -196,7 +212,7 @@ object MillInitSbtPlayFrameworkTests extends BuildGenTestSuite {
     test - integrationTest(url) { tester =>
       import tester.*
 
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")
@@ -220,7 +236,7 @@ object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
 
       bumpSbtTo1107(workspacePath)
 
-      val initResult = eval(initCommand, stdout = os.Inherit, stderr = os.Inherit)
+      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)
 
       val compileResult = eval("compile")

From f53312645297e7da4f45ad40f933ec6f1ecc8dc6 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sat, 22 Feb 2025 21:00:31 +0800
Subject: [PATCH 44/70] Reformat `GradleBuildGenMain.scala`

---
 .../gradle/src/mill/main/gradle/GradleBuildGenMain.scala   | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index 64ce64ac682..ee687544675 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -103,9 +103,10 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     file
   }
 
-  extension (om: ProjectModel) override def toOption(): Option[ProjectModel] =
-    // TODO consider filtering out projects without the `java` plugin applied
-    Some(om)
+  extension (om: ProjectModel)
+    override def toOption(): Option[ProjectModel] =
+      // TODO consider filtering out projects without the `java` plugin applied
+      Some(om)
 
   def getBaseInfo(
       input: Tree[Node[ProjectModel]],

From 6e48c2b8553d598971d4989c69c13fa997992836 Mon Sep 17 00:00:00 2001
From: "autofix-ci[bot]" <114827586+autofix-ci[bot]@users.noreply.github.com>
Date: Sat, 22 Feb 2025 13:16:22 +0000
Subject: [PATCH 45/70] [autofix.ci] apply automated fixes

---
 integration/feature/init/src/IntegrationTesterExt.scala | 2 +-
 integration/feature/init/src/MillInitSbtTests.scala     | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/integration/feature/init/src/IntegrationTesterExt.scala b/integration/feature/init/src/IntegrationTesterExt.scala
index e87f6ba043a..a1e99be9ca7 100644
--- a/integration/feature/init/src/IntegrationTesterExt.scala
+++ b/integration/feature/init/src/IntegrationTesterExt.scala
@@ -39,7 +39,7 @@ extension (tester: IntegrationTester)
         assert(!resolveAllTasksResult.isSuccess)
       )(expected => {
         assert(resolveAllTasksResult.isSuccess)
-        val resolvedAllTasks =  resolveAllTasksResult.out.split('\n').toSet
+        val resolvedAllTasks = resolveAllTasksResult.out.split('\n').toSet
         Predef.assert(resolvedAllTasks == expected.all, "resolved tasks: " + resolvedAllTasks)
 
         for (task <- expected.successful)
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index c9bb1e4bd31..278e90699f7 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -121,7 +121,7 @@ object MillInitZioHttpTests extends BuildGenTestSuite {
     test - integrationTest(url) { tester =>
       bumpSbtTo1107(tester.workspacePath)
 
-      val submodules = Seq(
+      Seq(
         "sbt-zio-http-grpc-tests",
         "sbt-zio-http-grpc",
         "zio-http-benchmarks.compile",

From 2286ed01d0b834d80148637d2b5c429874622f42 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 23 Feb 2025 03:01:39 +0800
Subject: [PATCH 46/70] Fix the integration tests failing on windows caused by
 `split('\n')`

An `java.io.IOException: Cannot run program "chmod"` exception thrown when the tests run in PowerShell is fixed BTW.
---
 integration/feature/init/src/IntegrationTesterExt.scala | 7 +++++--
 integration/feature/init/src/MillInitSbtTests.scala     | 4 +++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/integration/feature/init/src/IntegrationTesterExt.scala b/integration/feature/init/src/IntegrationTesterExt.scala
index a1e99be9ca7..76ef0a77371 100644
--- a/integration/feature/init/src/IntegrationTesterExt.scala
+++ b/integration/feature/init/src/IntegrationTesterExt.scala
@@ -39,8 +39,11 @@ extension (tester: IntegrationTester)
         assert(!resolveAllTasksResult.isSuccess)
       )(expected => {
         assert(resolveAllTasksResult.isSuccess)
-        val resolvedAllTasks = resolveAllTasksResult.out.split('\n').toSet
-        Predef.assert(resolvedAllTasks == expected.all, "resolved tasks: " + resolvedAllTasks)
+        val resolvedAllTasks = resolveAllTasksResult.out.linesIterator.toSet
+        Predef.assert(
+          expected.all == resolvedAllTasks,
+          "expected: " + expected.all + ", resolved: " + resolvedAllTasks
+        )
 
         for (task <- expected.successful)
           Predef.assert(eval(task).isSuccess, s"task $task failed")
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 278e90699f7..3560d5d9a84 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -1,5 +1,6 @@
 package mill.integration
 
+import mill.constants.Util
 import mill.integration.testMillInit
 import utest.*
 
@@ -161,7 +162,8 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
     test - integrationTest(url) { tester =>
       import tester.*
 
-      os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
+      if (!Util.isWindows)
+        os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
 
       val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
       assert(initResult.isSuccess)

From 768a2b104f97d0275a47b9e0f4e1f492dec647fd Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 23 Feb 2025 22:48:05 +0800
Subject: [PATCH 47/70] Fix the bug the converted sbt test modules extend
 `MavenTests` instead of `SbtTests` and update the unit test expected
 snapshots accordingly

---
 .../src/mill/main/buildgen/BuildGenUtil.scala      | 14 +++++++++-----
 main/init/buildgen/src/mill/main/buildgen/ir.scala |  2 ++
 .../src/mill/main/gradle/GradleBuildGenMain.scala  |  1 +
 .../src/mill/main/maven/MavenBuildGenMain.scala    |  1 +
 .../sbt/src/mill/main/sbt/SbtBuildGenMain.scala    |  1 +
 .../config/sbt-multi-project-example/build.mill    |  6 +++---
 .../sbt-multi-project-example/common/package.mill  |  2 +-
 .../sbt-multi-project-example/multi1/package.mill  |  2 +-
 .../sbt-multi-project-example/multi2/package.mill  |  2 +-
 .../expected/scala-seed-project/build.mill         |  2 +-
 10 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index ccc8dbce456..f1683c54a27 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -70,7 +70,7 @@ object BuildGenUtil {
       if (!hasTest) ""
       else {
         val declare =
-          BuildGenUtil.renderTestModuleDecl(testModule, scopedDeps.testModule)
+          BuildGenUtil.renderTestModuleDecl(testModule, testModuleMainType, scopedDeps.testModule)
 
         s"""$declare {
            |
@@ -482,11 +482,15 @@ object BuildGenUtil {
     }
   }
 
-  def renderTestModuleDecl(testModule: String, testModuleType: Option[String]): String = {
+  def renderTestModuleDecl(
+      testModule: String,
+      testModuleMainType: String,
+      testModuleExtraType: Option[String]
+  ): String = {
     val name = backtickWrap(testModule)
-    testModuleType match {
-      case Some(supertype) => s"object $name extends MavenTests with $supertype"
-      case None => s"trait $name extends MavenTests"
+    testModuleExtraType match {
+      case Some(supertype) => s"object $name extends $testModuleMainType with $supertype"
+      case None => s"trait $name extends $testModuleMainType"
     }
   }
 
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index 7fe838f1327..affdfe6ead5 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -81,6 +81,7 @@ case class IrLicense(
 case class IrBuild(
     scopedDeps: IrScopedDeps,
     testModule: String,
+    testModuleMainType: String,
     hasTest: Boolean,
     dirs: Seq[String],
     repositories: Seq[String],
@@ -102,6 +103,7 @@ object IrBuild {
   def empty(dirs: Seq[String]) = IrBuild(
     IrScopedDeps(),
     null,
+    null,
     false,
     dirs,
     Seq.empty,
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index ee687544675..a47d5a2a886 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -174,6 +174,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     IrBuild(
       scopedDeps = scopedDeps,
       testModule = cfg.shared.basicConfig.testModule,
+      testModuleMainType = "MavenTests",
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(project).diff(baseInfo.repositories),
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index 89af57b1b7a..dd5ec88aac6 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -113,6 +113,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
     IrBuild(
       scopedDeps = scopedDeps,
       testModule = cfg.shared.basicConfig.testModule,
+      testModuleMainType = "MavenTests",
       hasTest = os.exists(getMillSourcePath(model) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(model),
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 0acfc9df432..23e6f397ba4 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -249,6 +249,7 @@ object SbtBuildGenMain
     IrBuild(
       scopedDeps = configurationDeps,
       testModule = cfg.shared.testModule,
+      testModuleMainType = "SbtTests",
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(buildInfo).diff(baseInfo.repositories),
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index d3568bfed01..b6cd981a090 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -48,7 +48,7 @@ object `package` extends RootModule with BaseModule {
       Deps.`org.slf4j:jcl-over-slf4j`
     )
 
-    object tests extends MavenTests with TestModule.ScalaTest {
+    object tests extends SbtTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
         Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
@@ -71,7 +71,7 @@ object `package` extends RootModule with BaseModule {
 
     def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
-    object tests extends MavenTests with TestModule.ScalaTest {
+    object tests extends SbtTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
         Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
@@ -93,7 +93,7 @@ object `package` extends RootModule with BaseModule {
 
     def moduleDeps = super.moduleDeps ++ Seq(build.common)
 
-    object tests extends MavenTests with TestModule.ScalaTest {
+    object tests extends SbtTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
         Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
index d95ee7c1d5e..b4e5626284d 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -64,7 +64,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def publishVersion = "0.1.0-SNAPSHOT"
 
-  object test extends MavenTests with TestModule.ScalaTest {
+  object test extends SbtTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
index 80aea6a7077..ddd1fcbe2b9 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -68,7 +68,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def publishVersion = "0.1.0-SNAPSHOT"
 
-  object test extends MavenTests with TestModule.ScalaTest {
+  object test extends SbtTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
index c5df60d3df4..16bc9ddac87 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -67,7 +67,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def publishVersion = "0.1.0-SNAPSHOT"
 
-  object test extends MavenTests with TestModule.ScalaTest {
+  object test extends SbtTests with TestModule.ScalaTest {
 
     def ivyDeps = super.ivyDeps() ++ Seq(
       ivy"org.scalacheck::scalacheck:1.13.5",
diff --git a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
index a605637f48e..aa7f1f841a1 100644
--- a/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
+++ b/main/init/sbt/test/resources/expected/scala-seed-project/build.mill
@@ -22,7 +22,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
 
   def publishVersion = "0.1.0-SNAPSHOT"
 
-  object test extends MavenTests with TestModule.Munit {
+  object test extends SbtTests with TestModule.Munit {
 
     def ivyDeps = super.ivyDeps() ++ Seq(ivy"org.scalameta::munit:0.7.29")
 

From cd168ff7cdc4f7f30d9d8fd2ef59f9ac2bf88d53 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 23 Feb 2025 23:24:32 +0800
Subject: [PATCH 48/70] Update (fix) an integration test accordingly

---
 integration/feature/init/src/MillInitSbtTests.scala | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 3560d5d9a84..814be9fa80e 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -41,7 +41,7 @@ object MillInitScalaCsv200Tests extends BuildGenTestSuite {
       // Cross builds are not supported yet.
       tester.testMillInit(
         expectedCompileTasks = Some(SplitResolvedTasks(Seq(), Seq("compile", "test.compile"))),
-        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test" /*, "test.test"*/ )))
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test")))
       )
     }
   }
@@ -60,13 +60,10 @@ object MillInitScalaCsv136Tests extends BuildGenTestSuite {
 
       tester.testMillInit(
         expectedCompileTasks = Some(SplitResolvedTasks(
-          // It works here, but scala 2.11 with JDK 6 seems not supported when run with JDK 17 in shell.
-          Seq("compile"),
-          // `Not a Java dependency: Dep(Dependency(com.storm-enroute:scalameter, 0.8.2, Configuration(), Set(), Publication(, Type(), Extension(), Classifier()), false, true),Binary(false),false)`
-          // probably due to inheriting `MavenTests` instead of `SbtTests`
-          Seq("test.compile")
+          Seq("compile", "test.compile"),
+          Seq.empty
         )),
-        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test" /*, "test.test"*/ )))
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test")))
       )
     }
   }

From 9ee23dee3ebac7c2548b4c6b7f00dfc536d6c1a3 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Sun, 23 Feb 2025 23:43:12 +0800
Subject: [PATCH 49/70] Try fixing Mill `test` in the converted project of
 `MillInitScalaCsv136Tests` without success, and add a comment about it

---
 integration/feature/init/src/MillInitSbtTests.scala | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 814be9fa80e..ab80ca9c224 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -63,7 +63,17 @@ object MillInitScalaCsv136Tests extends BuildGenTestSuite {
           Seq("compile", "test.compile"),
           Seq.empty
         )),
-        expectedTestTasks = Some(SplitResolvedTasks(Seq(), Seq("test")))
+        expectedTestTasks = Some(SplitResolvedTasks(
+          Seq(),
+          /*
+          Relative paths to the workspace are used in the test sources such as `new File("src/test/resources/simple.csv")`
+          and they seem to cause the test to fail with Mill:
+          ```text
+          java.io.FileNotFoundException: src/test/resources/simple.csv (No such file or directory)
+          ```
+           */
+          Seq("test")
+        ))
       )
     }
   }

From 87afa17864805dec3aef1440ce8378b0b46fbd65 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 01:17:57 +0800
Subject: [PATCH 50/70] Move the `jvmId` config arg to `BasicConfig` and
 support it in `SbtBuildGenMain`, and update the tests (unit tests and
 integration tests) accordingly

---
 integration/feature/init/src/MillInitSbtTests.scala | 13 ++++++++++++-
 .../src/mill/main/buildgen/BuildGenUtil.scala       | 10 +++++-----
 .../src/mill/main/gradle/GradleBuildGenMain.scala   |  4 ++--
 .../src/mill/main/maven/MavenBuildGenMain.scala     |  2 +-
 .../sbt/src/mill/main/sbt/SbtBuildGenMain.scala     |  2 +-
 .../config/sbt-multi-project-example/build.mill     |  5 +++++
 .../sbt/test/src/mill/main/sbt/BuildGenTests.scala  |  2 ++
 7 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index ab80ca9c224..de0760bcf0a 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -95,6 +95,7 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
       val submodules = Seq("common", "multi1", "multi2")
 
       tester.testMillInit(
+        //initCommand = defaultInitCommand ++ Seq("--jvm-id", "11"),
         expectedCompileTasks =
           Some(if (System.getProperty("java.version").split('.').head.toInt <= 11)
             SplitResolvedTasks(
@@ -103,7 +104,17 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
               submodules.map(_.testCompileTask)
             )
           else {
-            // Submodules don't compile well with JDK 17 and 21, which seems to be due to incompatible bytecode versions in dependencies.
+            /*
+            `multi1.compile` doesn't work well when Mill is run with JDK 17 and 21:
+            ```text
+            1 tasks failed
+            multi1.compile java.io.IOError: java.lang.RuntimeException: /packages cannot be represented as URI
+                java.base/jdk.internal.jrtfs.JrtPath.toUri(JrtPath.java:175)
+                scala.tools.nsc.classpath.JrtClassPath.asURLs(DirectoryClassPath.scala:183)
+                ...
+            ```
+            Passing a `jvmId` 11 doesn't work.
+             */
             val succeededSubmoduleCompileTasks = Seq("common.compile", "multi2.compile")
             SplitResolvedTasks(
               Seq("compile") ++ succeededSubmoduleCompileTasks,
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index f1683c54a27..c62336ac728 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -498,6 +498,11 @@ object BuildGenUtil {
   case class BasicConfig(
       @arg(doc = "name of generated base module trait defining shared settings", short = 'b')
       baseModule: Option[String] = None,
+      @arg(
+        doc = "distribution and version of custom JVM to configure in --base-module",
+        short = 'j'
+      )
+      jvmId: Option[String] = None,
       @arg(doc = "name of generated nested test module", short = 't')
       testModule: String = "test",
       @arg(doc = "name of generated companion object defining dependency constants", short = 'd')
@@ -512,11 +517,6 @@ object BuildGenUtil {
   @mainargs.main
   case class Config(
       basicConfig: BasicConfig,
-      @arg(
-        doc = "distribution and version of custom JVM to configure in --base-module",
-        short = 'j'
-      )
-      jvmId: Option[String] = None,
       @arg(doc = "capture Maven publish properties", short = 'p')
       publishProperties: Flag = Flag()
   )
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index a47d5a2a886..e32b6580a11 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -55,7 +55,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     val connector = GradleConnector.newConnector()
 
     val args =
-      cfg.shared.jvmId.map { id =>
+      cfg.shared.basicConfig.jvmId.map { id =>
         println(s"resolving Java home for jvmId $id")
         val home = Jvm.resolveJavaHome(id).get
         s"-Dorg.gradle.java.home=$home"
@@ -138,7 +138,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     val publishProperties = getPublishProperties(project, cfg.shared)
 
     val typedef = IrTrait(
-      cfg.shared.jvmId,
+      cfg.shared.basicConfig.jvmId,
       baseModule,
       supertypes,
       javacOptions,
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index dd5ec88aac6..4660229315a 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -77,7 +77,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
     val publishProperties = getPublishProperties(model, cfg.shared)
 
     val typedef = IrTrait(
-      cfg.shared.jvmId,
+      cfg.shared.basicConfig.jvmId,
       baseModule,
       getModuleSupertypes(cfg),
       javacOptions,
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 23e6f397ba4..b33f6a3767c 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -212,7 +212,7 @@ object SbtBuildGenMain
     val publishVersion = getPublishVersion(buildInfo)
 
     val typedef = IrTrait(
-      None, // There doesn't seem to be a Java version setting in sbt. See https://stackoverflow.com/a/76456295/5082913.
+      cfg.shared.jvmId, // There doesn't seem to be a Java version setting in sbt though. See https://stackoverflow.com/a/76456295/5082913.
       baseModule,
       sbtSupertypes,
       javacOptions,
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
index b6cd981a090..a87471bad19 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
@@ -157,4 +157,9 @@ trait BaseModule extends SbtModule with PublishModule {
     )
   }
 
+  def zincWorker = mill.define.ModuleRef(BaseModuleZincWorker)
+
+  object BaseModuleZincWorker extends ZincWorkerModule {
+    def jvmId = "11"
+  }
 }
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index 3708220fe81..f031147a1ce 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -31,6 +31,8 @@ object BuildGenTests extends TestSuite {
       val args = Array(
         "--base-module",
         "BaseModule",
+        "--jvm-id",
+        "11",
         "--test-module",
         "tests",
         "--deps-object",

From 02206a6bc8cce12198e2d5e0a11c1b54c230cede Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 03:19:17 +0800
Subject: [PATCH 51/70] Support the `baseProject` config arg too in
 `SbtBuildGenMain` and update the expected snapshots in test resources
 accordingly

---
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  17 +-
 .../all/sbt-multi-project-example/build.mill  | 261 ++++++++++++++++++
 .../sbt-multi-project-example/build.mill      |  23 ++
 .../common/package.mill                       |   2 +-
 .../sbt-multi-project-example/build.sbt       |   2 +-
 .../src/mill/main/sbt/BuildGenTests.scala     |  27 +-
 6 files changed, 320 insertions(+), 12 deletions(-)
 create mode 100644 main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
 rename main/init/sbt/test/resources/expected/config/{ => without-base-project}/sbt-multi-project-example/build.mill (88%)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index b33f6a3767c..be87963d5cf 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -1,6 +1,6 @@
 package mill.main.sbt
 
-import mainargs.{ParserForClass, main}
+import mainargs.{ParserForClass, arg, main}
 import mill.constants.Util
 import mill.main.buildgen.*
 import mill.main.buildgen.BuildGenUtil.*
@@ -203,7 +203,12 @@ object SbtBuildGenMain
       baseModule: String,
       packagesSize: Int
   ): IrBaseInfo = {
-    val buildInfo = input._1
+    val buildInfo = cfg.baseProject.fold(input._1)(name =>
+      // TODO This can simplified if `buildExport.projects` is passed here.
+      input._2.nodes().collectFirst(Function.unlift(_.value.flatMap(project =>
+        Option.when(project.name == name)(project)
+      ))).get.buildInfo
+    )
 
     import buildInfo.*
     val javacOptions = getJavacOptions(buildInfo)
@@ -470,6 +475,12 @@ object SbtBuildGenMain
   @main
   @mill.api.internal
   case class Config(
-      shared: BuildGenUtil.BasicConfig
+      shared: BuildGenUtil.BasicConfig,
+      @arg(
+        doc = "name of the sbt project to extract settings for --base-module, " +
+          "if not specified, settings are extracted from `ThisBuild`",
+        short = 'g'
+      )
+      baseProject: Option[String] = None
   )
 }
diff --git a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
new file mode 100644
index 00000000000..8e5e0a141bd
--- /dev/null
+++ b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
@@ -0,0 +1,261 @@
+package build
+
+import mill._
+import mill.javalib._
+import mill.javalib.publish._
+import mill.scalalib.SbtModule
+
+object Deps {
+
+  val `ch.qos.logback:logback-classic` =
+    ivy"ch.qos.logback:logback-classic:1.2.3"
+
+  val `com.github.julien-truffaut:monocle-core` =
+    ivy"com.github.julien-truffaut::monocle-core:1.4.0"
+
+  val `com.github.julien-truffaut:monocle-macro` =
+    ivy"com.github.julien-truffaut::monocle-macro:1.4.0"
+
+  val `com.github.pureconfig:pureconfig` =
+    ivy"com.github.pureconfig::pureconfig:0.8.0"
+
+  val `com.typesafe.akka:akka-stream` =
+    ivy"com.typesafe.akka::akka-stream:2.5.6"
+
+  val `com.typesafe.scala-logging:scala-logging` =
+    ivy"com.typesafe.scala-logging::scala-logging:3.7.2"
+  val `com.typesafe:config` = ivy"com.typesafe:config:1.3.1"
+
+  val `net.logstash.logback:logstash-logback-encoder` =
+    ivy"net.logstash.logback:logstash-logback-encoder:4.11"
+  val `org.scalacheck:scalacheck` = ivy"org.scalacheck::scalacheck:1.13.5"
+  val `org.scalatest:scalatest` = ivy"org.scalatest::scalatest:3.0.4"
+  val `org.slf4j:jcl-over-slf4j` = ivy"org.slf4j:jcl-over-slf4j:1.7.25"
+}
+
+object `package` extends RootModule with BaseModule {
+
+  def artifactName = "sbt-multi-project-example"
+
+  def pomSettings = PomSettings(
+    "This is an sbt sample project for testing Mill's init command.",
+    "com.pbassiner",
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
+  )
+
+  object common extends BaseModule {
+
+    def ivyDeps = super.ivyDeps() ++ Seq(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    object tests extends SbtTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+
+  object multi1 extends BaseModule {
+
+    def ivyDeps = super.ivyDeps() ++ Seq(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.github.julien-truffaut:monocle-core`,
+      Deps.`com.github.julien-truffaut:monocle-macro`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+    def pomSettings = PomSettings(
+      "This is an sbt sample project for testing Mill's init command.",
+      "com.pbassiner",
+      "https://github.com/com-lihaoyi/mill",
+      Seq(License(
+        "Apache-2.0",
+        "Apache-2.0",
+        "https://www.apache.org/licenses/LICENSE-2.0.txt",
+        false,
+        false,
+        "repo"
+      )),
+      VersionControl(
+        Some("https://github.com/com-lihaoyi/mill"),
+        Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+        None,
+        None
+      ),
+      Seq(
+        Developer("johnd", "John Doe", "https://example.com/johnd", None, None)
+      )
+    )
+
+    object tests extends SbtTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+
+  object multi2 extends BaseModule {
+
+    def ivyDeps = super.ivyDeps() ++ Seq(
+      Deps.`ch.qos.logback:logback-classic`,
+      Deps.`com.github.pureconfig:pureconfig`,
+      Deps.`com.typesafe.akka:akka-stream`,
+      Deps.`com.typesafe.scala-logging:scala-logging`,
+      Deps.`com.typesafe:config`,
+      Deps.`net.logstash.logback:logstash-logback-encoder`,
+      Deps.`org.slf4j:jcl-over-slf4j`
+    )
+
+    def moduleDeps = super.moduleDeps ++ Seq(build.common)
+
+    def pomSettings = PomSettings(
+      "This is an sbt sample project for testing Mill's init command.",
+      "com.pbassiner",
+      "https://github.com/com-lihaoyi/mill",
+      Seq(License(
+        "Apache-2.0",
+        "Apache-2.0",
+        "https://www.apache.org/licenses/LICENSE-2.0.txt",
+        false,
+        false,
+        "repo"
+      )),
+      VersionControl(
+        Some("https://github.com/com-lihaoyi/mill"),
+        Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+        None,
+        None
+      ),
+      Seq(
+        Developer("johnd", "John Doe", "https://example.com/johnd", None, None)
+      )
+    )
+
+    object tests extends SbtTests with TestModule.ScalaTest {
+
+      def ivyDeps = super.ivyDeps() ++
+        Seq(Deps.`org.scalacheck:scalacheck`, Deps.`org.scalatest:scalatest`)
+
+    }
+  }
+
+  object nested extends Module {
+
+    object nested extends BaseModule {
+
+      def pomSettings = PomSettings(
+        "This is an sbt sample project for testing Mill's init command.",
+        "com.pbassiner",
+        "https://github.com/com-lihaoyi/mill",
+        Seq(License(
+          "Apache-2.0",
+          "Apache-2.0",
+          "https://www.apache.org/licenses/LICENSE-2.0.txt",
+          false,
+          false,
+          "repo"
+        )),
+        VersionControl(
+          Some("https://github.com/com-lihaoyi/mill"),
+          Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+          None,
+          None
+        ),
+        Seq(Developer(
+          "johnd",
+          "John Doe",
+          "https://example.com/johnd",
+          None,
+          None
+        ))
+      )
+
+    }
+  }
+}
+
+trait BaseModule extends SbtModule with PublishModule {
+
+  def scalaVersion = "2.12.3"
+
+  def scalacOptions = super.scalacOptions() ++ Seq(
+    "-unchecked",
+    "-feature",
+    "-language:existentials",
+    "-language:higherKinds",
+    "-language:implicitConversions",
+    "-language:postfixOps",
+    "-deprecation",
+    "-encoding",
+    "utf8"
+  )
+
+  def pomSettings = PomSettings(
+    "This is the common module.",
+    "com.pbassiner",
+    "https://github.com/com-lihaoyi/mill",
+    Seq(License(
+      "Apache-2.0",
+      "Apache-2.0",
+      "https://www.apache.org/licenses/LICENSE-2.0.txt",
+      false,
+      false,
+      "repo"
+    )),
+    VersionControl(
+      Some("https://github.com/com-lihaoyi/mill"),
+      Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+      None,
+      None
+    ),
+    Seq(Developer("johnd", "John Doe", "https://example.com/johnd", None, None))
+  )
+
+  def publishVersion = "0.1.0-SNAPSHOT"
+
+  def repositoriesTask = Task.Anon {
+    super.repositoriesTask() ++ Seq(
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/service/local/repositories/releases/content/"
+      ),
+      coursier.maven.MavenRepository(
+        "https://oss.sonatype.org/content/repositories/snapshots"
+      )
+    )
+  }
+
+  def zincWorker = mill.define.ModuleRef(BaseModuleZincWorker)
+
+  object BaseModuleZincWorker extends ZincWorkerModule {
+    def jvmId = "11"
+  }
+}
diff --git a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
similarity index 88%
rename from main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
rename to main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
index a87471bad19..de6ca5569e5 100644
--- a/main/init/sbt/test/resources/expected/config/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
@@ -48,6 +48,29 @@ object `package` extends RootModule with BaseModule {
       Deps.`org.slf4j:jcl-over-slf4j`
     )
 
+    def pomSettings = PomSettings(
+      "This is the common module.",
+      "com.pbassiner",
+      "https://github.com/com-lihaoyi/mill",
+      Seq(License(
+        "Apache-2.0",
+        "Apache-2.0",
+        "https://www.apache.org/licenses/LICENSE-2.0.txt",
+        false,
+        false,
+        "repo"
+      )),
+      VersionControl(
+        Some("https://github.com/com-lihaoyi/mill"),
+        Some("scm:git:https://github.com/com-lihaoyi/mill.git"),
+        None,
+        None
+      ),
+      Seq(
+        Developer("johnd", "John Doe", "https://example.com/johnd", None, None)
+      )
+    )
+
     object tests extends SbtTests with TestModule.ScalaTest {
 
       def ivyDeps = super.ivyDeps() ++
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
index b4e5626284d..72e8561ca20 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/common/package.mill
@@ -42,7 +42,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
   )
 
   def pomSettings = PomSettings(
-    "This is an sbt sample project for testing Mill's init command.",
+    "This is the common module.",
     "com.pbassiner",
     "https://github.com/com-lihaoyi/mill",
     Seq(License(
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index 64f33161bda..f6e0ad0168d 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -24,7 +24,7 @@ lazy val global = project
 lazy val common = project
   .settings(
     name := "common",
-    settings,
+    settings ++ Seq(description := "This is the common module."),
     libraryDependencies ++= commonDependencies
   )
   .disablePlugins(AssemblyPlugin)
diff --git a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
index f031147a1ce..2a15135d51a 100644
--- a/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
+++ b/main/init/sbt/test/src/mill/main/sbt/BuildGenTests.scala
@@ -25,10 +25,8 @@ object BuildGenTests extends TestSuite {
       )
     }
 
-    test("config-sbt-multi-project-example") {
-      val sourceRoot = os.sub / "sbt-multi-project-example"
-      val expectedRoot = os.sub / "expected/config/sbt-multi-project-example"
-      val args = Array(
+    test("config") {
+      val commonArgs = Array(
         "--base-module",
         "BaseModule",
         "--jvm-id",
@@ -39,9 +37,24 @@ object BuildGenTests extends TestSuite {
         "Deps",
         "--merge"
       )
-      assert(
-        checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot)
-      )
+      test("sbt-multi-project-example") {
+        val sourceRoot = os.sub / "sbt-multi-project-example"
+        test("without-base-project") {
+          val expectedRoot =
+            os.sub / "expected/config/without-base-project/sbt-multi-project-example"
+          val args = commonArgs
+          assert(
+            checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot)
+          )
+        }
+        test("all") {
+          val expectedRoot = os.sub / "expected/config/all/sbt-multi-project-example"
+          val args = commonArgs ++ Array("--baseProject", "common")
+          assert(
+            checker.check(SbtBuildGenMain.main(args), sourceRoot, expectedRoot)
+          )
+        }
+      }
     }
   }
 }

From c819207ff0e8ad7ad81304ba448e07fa00d85629 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 05:16:13 +0800
Subject: [PATCH 52/70] Fix assertions in `MillInitSbtMultiProjectExampleTests`
 that fail due to commit 768a2b104f97d0275a47b9e0f4e1f492dec647fd

---
 integration/feature/init/src/MillInitSbtTests.scala | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index de0760bcf0a..6d002f52fcb 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -95,14 +95,10 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
       val submodules = Seq("common", "multi1", "multi2")
 
       tester.testMillInit(
-        //initCommand = defaultInitCommand ++ Seq("--jvm-id", "11"),
+        // initCommand = defaultInitCommand ++ Seq("--jvm-id", "11"),
         expectedCompileTasks =
           Some(if (System.getProperty("java.version").split('.').head.toInt <= 11)
-            SplitResolvedTasks(
-              Seq("compile") ++ submodules.map(_.compileTask),
-              // probably due to inheriting `MavenTests` instead of `SbtTests`
-              submodules.map(_.testCompileTask)
-            )
+            SplitResolvedTasks(Seq("compile") ++ submodules.flatMap(_.allCompileTasks), Seq.empty)
           else {
             /*
             `multi1.compile` doesn't work well when Mill is run with JDK 17 and 21:

From 22033e909dd461689b374815ca4602b087b8830f Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 10:53:04 +0800
Subject: [PATCH 53/70] Support comparing a module's `def`'s with and extending
 super base module's `def`s in converted builds as required in
 https://github.com/com-lihaoyi/mill/pull/4586#issuecomment-2674530292

- Refactor some types to use Scala 3 explicit nulls BTW.
- Fix a bug that `pomSettings` in modules different from that in the base module is lost in builds converted from Maven, BTW.
- Update unit test code to test the changes and the expected snapshots in test resources correspondingly.
---
 .../src/mill/main/buildgen/BuildGenBase.scala |   6 +-
 .../src/mill/main/buildgen/BuildGenUtil.scala | 134 +++++++++++++-----
 .../buildgen/src/mill/main/buildgen/ir.scala  |  19 ++-
 .../mill/main/gradle/GradleBuildGenMain.scala |  30 ++--
 .../mill/main/maven/MavenBuildGenMain.scala   |  21 +--
 .../test/resources/expected/config/build.mill |  56 ++++++++
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  32 ++---
 .../all/sbt-multi-project-example/build.mill  |  12 ++
 .../sbt-multi-project-example/build.mill      |  12 ++
 .../multi1/package.mill                       |   3 +-
 .../multi2/package.mill                       |   4 +-
 .../sbt-multi-project-example/build.sbt       |  12 +-
 12 files changed, 230 insertions(+), 111 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 5feaf83e372..0cfd344c391 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -49,7 +49,7 @@ trait BuildGenBase[M, D, I] {
           println(s"converting module $name")
 
           val build = optionalBuild.copy(value = moduleModel)
-          val inner = extractIrBuild(cfg, baseInfo, build, packages)
+          val inner = extractIrBuild(cfg, build, packages)
 
           val isNested = optionalBuild.dirs.nonEmpty
           BuildObject(
@@ -60,7 +60,7 @@ trait BuildGenBase[M, D, I] {
                 SortedMap((name, SortedMap(inner.scopedDeps.namedIvyDeps.toSeq*)))
               ),
             supertypes = getSupertypes(cfg, baseInfo, build),
-            inner = BuildGenUtil.renderIrBuild(inner),
+            inner = BuildGenUtil.renderIrBuild(inner, baseInfo),
             outer =
               if (isNested || baseInfo.moduleTypedef == null) ""
               else BuildGenUtil.renderIrTrait(baseInfo.moduleTypedef)
@@ -87,7 +87,7 @@ trait BuildGenBase[M, D, I] {
 
   def extractIrBuild(
       cfg: C,
-      baseInfo: IrBaseInfo,
+      // baseInfo: IrBaseInfo, // `baseInfo` is no longer needed as we compare the `IrBuild` with `IrBaseInfo`/`IrTrait` in common code now.
       build: Node[M],
       packages: Map[(String, String, String), String]
   ): IrBuild
diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index c62336ac728..ef415327b16 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -51,10 +51,7 @@ object BuildGenUtil {
 
   }
 
-  def takeIrPomIfNeeded(baseInfo: IrBaseInfo, irPom: IrPom): IrPom =
-    if (baseInfo.noPom || irPom != baseInfo.moduleTypedef.pomSettings) irPom else null
-
-  def renderIrPom(value: IrPom): String = {
+  def renderIrPom(value: IrPom | Null): String = {
     if (value == null) ""
     else {
       import value.*
@@ -64,8 +61,12 @@ object BuildGenUtil {
     }
   }
 
-  def renderIrBuild(value: IrBuild): String = {
-    import value.*
+  /**
+   * @param baseInfo to compare with [[build]] and render the values only if they are different.
+   */
+  def renderIrBuild(build: IrBuild, baseInfo: IrBaseInfo): String = {
+    val baseTrait = baseInfo.moduleTypedef
+    import build.*
     val testModuleTypedef =
       if (!hasTest) ""
       else {
@@ -90,13 +91,22 @@ object BuildGenUtil {
 
     s"""${renderArtifactName(projectName, dirs)}
        |
-       |${renderJavacOptions(javacOptions)}
+       |${renderJavacOptions(
+        javacOptions,
+        if (baseTrait != null) baseTrait.javacOptions else Seq.empty
+      )}
        |
-       |${renderScalaVersion(scalaVersion)}
+       |${renderScalaVersion(scalaVersion, if (baseTrait != null) baseTrait.scalaVersion else None)}
        |
-       |${renderScalacOptions(scalacOptions)}
+       |${renderScalacOptions(
+        scalacOptions,
+        if (baseTrait != null) baseTrait.scalacOptions else None
+      )}
        |
-       |${renderRepositories(repositories)}
+       |${renderRepositories(
+        repositories,
+        if (baseTrait != null) baseTrait.repositories else Seq.empty
+      )}
        |
        |${renderBomIvyDeps(scopedDeps.mainBomIvyDeps)}
        |
@@ -112,9 +122,16 @@ object BuildGenUtil {
        |
        |${renderRunModuleDeps(scopedDeps.mainRunModuleDeps)}
        |
-       |${if (pomSettings == null) "" else renderPomSettings(renderIrPom(pomSettings))}
+       |${
+        if (pomSettings != (if (baseTrait != null) baseTrait.pomSettings else null))
+          renderPomSettings(renderIrPom(pomSettings))
+        else ""
+      }
        |
-       |${renderPublishVersion(publishVersion)}
+       |${renderPublishVersion(
+        publishVersion,
+        if (baseTrait != null) baseTrait.publishVersion else null
+      )}
        |
        |${renderPomPackaging(packaging)}
        |
@@ -303,7 +320,7 @@ object BuildGenUtil {
   def isBom(groupArtifactVersion: (String, String, String)): Boolean =
     groupArtifactVersion._2.endsWith("-bom")
 
-  def isNullOrEmpty(value: String): Boolean =
+  def isNullOrEmpty(value: String | Null): Boolean =
     null == value || value.isEmpty
 
   val linebreak: String =
@@ -347,6 +364,7 @@ object BuildGenUtil {
        |  def jvmId = "$jvmId"
        |}""".stripMargin
 
+  // TODO consider renaming to `renderOptionalDef` or `renderIfArgsNonEmpty`?
   def optional(construct: String, args: IterableOnce[String]): String =
     optional(construct + "(", args, ",", ")")
 
@@ -356,6 +374,43 @@ object BuildGenUtil {
     else itr.mkString(start, sep, end)
   }
 
+  def renderStringSeqWithSuper(
+      defName: String,
+      args: Seq[String],
+      superArgs: Seq[String] = Seq.empty,
+      transform: String => String
+  ): Option[String] =
+    if (args.startsWith(superArgs)) {
+      val superLength = superArgs.length
+      if (args.length == superLength) None
+      else
+        // Note that the super def is called even when it's empty.
+        // Some super functions can be called without parentheses, but we just add it here for simplicity.
+        Some(optional(
+          s"super.$defName() ++ Seq",
+          args.iterator.drop(superLength).map(transform)
+        ))
+    } else
+      Some(optional(s"Seq", args.iterator.map(transform)))
+
+  def renderStringSeqTargetDefWithSuper(
+      defName: String,
+      args: Seq[String],
+      superArgs: Seq[String] = Seq.empty,
+      transform: String => String
+  ) =
+    renderStringSeqWithSuper(defName, args, superArgs, transform).map(s"def $defName = " + _)
+
+  def renderStringSeqTaskDefWithSuper(
+      defName: String,
+      args: Seq[String],
+      superArgs: Seq[String] = Seq.empty,
+      transform: String => String
+  ) =
+    renderStringSeqWithSuper(defName, args, superArgs, transform).map(s =>
+      s"def $defName = Task.Anon { $s }"
+    )
+
   def scalafmtConfigFile: os.Path =
     os.temp(
       """version = "3.8.4"
@@ -394,30 +449,26 @@ object BuildGenUtil {
   def renderRunModuleDeps(args: IterableOnce[String]): String =
     optional("def runModuleDeps = super.runModuleDeps ++ Seq", args)
 
-  def renderJavacOptions(args: IterableOnce[String]): String =
-    optional(
-      "def javacOptions = super.javacOptions() ++ Seq",
-      args.iterator.map(escape)
-    )
+  def renderJavacOptions(args: Seq[String], superArgs: Seq[String] = Seq.empty): String =
+    renderStringSeqTargetDefWithSuper("javacOptions", args, superArgs, escape).getOrElse("")
 
-  def renderScalaVersion(scalaVersion: Option[String]): String =
-    scalaVersion.fold("")(scalaVersion => s"def scalaVersion = ${escape(scalaVersion)}")
+  def renderScalaVersion(arg: Option[String], superArg: Option[String] = None): String =
+    if (arg != superArg) arg.fold("")(scalaVersion => s"def scalaVersion = ${escape(scalaVersion)}")
+    else ""
 
-  def renderScalacOptions(args: Option[IterableOnce[String]]): String =
-    args.fold("")(args =>
-      optional(
-        "def scalacOptions = super.scalacOptions() ++ Seq",
-        args.iterator.map(escape)
-      )
-    )
+  def renderScalacOptions(
+      args: Option[Seq[String]],
+      superArgs: Option[Seq[String]] = None
+  ): String =
+    renderStringSeqTargetDefWithSuper(
+      "scalacOptions",
+      args.getOrElse(Seq.empty),
+      superArgs.getOrElse(Seq.empty),
+      escape
+    ).getOrElse("")
 
-  def renderRepositories(args: IterableOnce[String]): String =
-    optional(
-      "def repositoriesTask = Task.Anon { super.repositoriesTask() ++ Seq(",
-      args,
-      ", ",
-      ") }"
-    )
+  def renderRepositories(args: Seq[String], superArgs: Seq[String] = Seq.empty): String =
+    renderStringSeqTaskDefWithSuper("repositoriesTask", args, superArgs, identity).getOrElse("")
 
   def renderResources(args: IterableOnce[os.SubPath]): String =
     optional(
@@ -438,15 +489,20 @@ object BuildGenUtil {
     if (isNullOrEmpty(artifact)) ""
     else s"def pomParentProject = Some($artifact)"
 
-  def renderPomSettings(arg: String): String =
+  def renderPomSettings(arg: String | Null, superArg: String | Null = null): String =
     if (isNullOrEmpty(arg)) ""
     else s"def pomSettings = $arg"
 
-  def renderPublishVersion(arg: String): String =
-    if (isNullOrEmpty(arg)) ""
-    else s"def publishVersion = ${escape(arg)}"
+  def renderPublishVersion(arg: String | Null, superArg: String | Null = null): String =
+    if (arg != superArg)
+      if (isNullOrEmpty(arg)) ""
+      else s"def publishVersion = ${escape(arg)}"
+    else ""
 
-  def renderPublishProperties(args: IterableOnce[(String, String)]): String = {
+  def renderPublishProperties(
+      args: Seq[(String, String)],
+      superArgs: Seq[(String, String)] = Seq.empty
+  ): String = {
     val tuples = args.iterator.map { case (k, v) => s"(${escape(k)}, ${escape(v)})" }
     optional("def publishProperties = super.publishProperties() ++ Map", tuples)
   }
diff --git a/main/init/buildgen/src/mill/main/buildgen/ir.scala b/main/init/buildgen/src/mill/main/buildgen/ir.scala
index affdfe6ead5..bb9fa119297 100644
--- a/main/init/buildgen/src/mill/main/buildgen/ir.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/ir.scala
@@ -43,8 +43,8 @@ case class IrTrait(
     javacOptions: Seq[String],
     scalaVersion: Option[String],
     scalacOptions: Option[Seq[String]],
-    pomSettings: IrPom,
-    publishVersion: String,
+    pomSettings: IrPom | Null,
+    publishVersion: String | Null,
     publishProperties: Seq[(String, String)],
     repositories: Seq[String]
 )
@@ -78,6 +78,7 @@ case class IrLicense(
 )
 
 // TODO Consider renaming to `IrModule(Build)` to disambiguate? sbt, for example, uses `ThisBuild` and `buildSettings` to refer to the whole build.
+// TODO reuse the members in `IrTrait`?
 case class IrBuild(
     scopedDeps: IrScopedDeps,
     testModule: String,
@@ -89,10 +90,10 @@ case class IrBuild(
     scalaVersion: Option[String],
     scalacOptions: Option[Seq[String]],
     projectName: String,
-    pomSettings: IrPom,
-    publishVersion: String,
-    packaging: String,
-    pomParentArtifact: IrArtifact,
+    pomSettings: IrPom | Null,
+    publishVersion: String | Null,
+    packaging: String | Null,
+    pomParentArtifact: IrArtifact | Null,
     resources: Seq[os.SubPath],
     testResources: Seq[os.SubPath],
     publishProperties: Seq[(String, String)]
@@ -139,7 +140,9 @@ case class IrScopedDeps(
     testCompileModuleDeps: SortedSet[String] = SortedSet()
 )
 
+// TODO remove `IrBaseInfo` and just use `IrTrait` directly?
 case class IrBaseInfo(
+    /*
     javacOptions: Seq[String] = Nil,
     scalaVersion: Option[String] = None,
     scalacOptions: Option[Seq[String]] = None,
@@ -147,7 +150,9 @@ case class IrBaseInfo(
     noPom: Boolean = true,
     publishVersion: String = "",
     publishProperties: Seq[(String, String)] = Nil,
-    moduleTypedef: IrTrait = null
+     */
+    // TODO consider renaming directly to `trait` or `baseTrait`?
+    moduleTypedef: IrTrait | Null = null
 )
 
 sealed class IrDependencyType
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index e32b6580a11..da0620bba53 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -150,21 +150,12 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
       repos
     )
 
-    IrBaseInfo(
-      javacOptions,
-      scalaVersion,
-      scalacOptions,
-      repos,
-      pomSettings == null,
-      publishVersion,
-      Seq.empty,
-      typedef
-    )
+    IrBaseInfo(typedef)
   }
 
   override def extractIrBuild(
       cfg: Config,
-      baseInfo: IrBaseInfo,
+      // baseInfo: IrBaseInfo,
       build: Node[ProjectModel],
       packages: Map[(String, String, String), String]
   ): IrBuild = {
@@ -177,13 +168,13 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
       testModuleMainType = "MavenTests",
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
-      repositories = getRepositories(project).diff(baseInfo.repositories),
-      javacOptions = getJavacOptions(project).diff(baseInfo.javacOptions),
+      repositories = getRepositories(project),
+      javacOptions = getJavacOptions(project),
       scalaVersion = None,
       scalacOptions = None,
       projectName = getArtifactId(project),
-      pomSettings = if (baseInfo.noPom) extractPomSettings(project) else null,
-      publishVersion = if (version == baseInfo.publishVersion) null else version,
+      pomSettings = extractPomSettings(project),
+      publishVersion = version,
       packaging = getPomPackaging(project),
       // not available
       pomParentArtifact = null,
@@ -209,7 +200,10 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
 
   def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] =
     Seq("RootModule") ++
-      Option.when(null != build.value.maven().pom() && baseInfo.noPom) { "PublishModule" } ++
+      Option.when(null != build.value.maven().pom() && {
+        val baseTrait = baseInfo.moduleTypedef
+        baseTrait == null || !baseTrait.moduleSupertypes.contains("PublishModule")
+      }) { "PublishModule" } ++
       Option.when(build.dirs.nonEmpty || os.exists(getMillSourcePath(build.value) / "src")) {
         getModuleSupertypes(cfg)
       }.toSeq.flatten
@@ -242,7 +236,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
         .toSeq
     } else Seq.empty
 
-  def getPublishVersion(project: ProjectModel): String =
+  def getPublishVersion(project: ProjectModel): String | Null =
     project.version() match {
       case "" | "unspecified" => null
       case version => version
@@ -252,7 +246,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     BuildGenUtil.renderIvyString(dep.group(), dep.name(), dep.version())
   }
 
-  def extractPomSettings(project: ProjectModel): IrPom = {
+  def extractPomSettings(project: ProjectModel): IrPom | Null = {
     val pom = project.maven.pom()
     if (null == pom) null
     else {
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index 4660229315a..ef79db544c0 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -89,21 +89,12 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
       getRepositories(model)
     )
 
-    IrBaseInfo(
-      javacOptions,
-      scalaVersion,
-      scalacOptions,
-      repositories,
-      noPom = false,
-      publishVersion,
-      publishProperties,
-      typedef
-    )
+    IrBaseInfo(typedef)
   }
 
   override def extractIrBuild(
       cfg: Config,
-      baseInfo: IrBaseInfo,
+      // baseInfo: IrBaseInfo,
       build: Node[Model],
       packages: Map[(String, String, String), String]
   ): IrBuild = {
@@ -117,12 +108,12 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
       hasTest = os.exists(getMillSourcePath(model) / "src/test"),
       dirs = build.dirs,
       repositories = getRepositories(model),
-      javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model).diff(baseInfo.javacOptions),
+      javacOptions = Plugins.MavenCompilerPlugin.javacOptions(model),
       scalaVersion = None,
       scalacOptions = None,
       projectName = getArtifactId(model),
-      pomSettings = if (baseInfo.noPom) extractPomSettings(model) else null,
-      publishVersion = if (version == baseInfo.publishVersion) null else version,
+      pomSettings = extractPomSettings(model),
+      publishVersion = version,
       packaging = model.getPackaging,
       pomParentArtifact = mkPomParent(model.getParent),
       resources =
@@ -131,7 +122,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
       testResources =
         processResources(model.getBuild.getTestResources, getMillSourcePath(model))
           .filterNot(_ == mavenTestResourceDir),
-      publishProperties = getPublishProperties(model, cfg.shared).diff(baseInfo.publishProperties)
+      publishProperties = getPublishProperties(model, cfg.shared)
     )
   }
 
diff --git a/main/init/maven/test/resources/expected/config/build.mill b/main/init/maven/test/resources/expected/config/build.mill
index 9cf6310e09c..9d563d4bfb2 100644
--- a/main/init/maven/test/resources/expected/config/build.mill
+++ b/main/init/maven/test/resources/expected/config/build.mill
@@ -27,6 +27,20 @@ object `package` extends RootModule with MyModule {
     def javacOptions = super.javacOptions() ++
       Seq("-source", "1.6", "-target", "1.6")
 
+    def pomSettings = PomSettings(
+      "Sample multi module Maven project with a working, deployable site.",
+      "com.example.maven-samples",
+      "http://www.example.com",
+      Seq(),
+      VersionControl(
+        Some("http://github.com/gabrielf/maven-samples"),
+        Some("scm:git:git@github.com:gabrielf/maven-samples.git"),
+        Some("scm:git:git@github.com:gabrielf/maven-samples.git"),
+        Some("HEAD")
+      ),
+      Seq()
+    )
+
     def pomPackagingType = PackagingType.Pom
 
     def publishProperties = super.publishProperties() ++ Map(
@@ -39,6 +53,20 @@ object `package` extends RootModule with MyModule {
       def javacOptions = super.javacOptions() ++
         Seq("-source", "1.6", "-target", "1.6")
 
+      def pomSettings = PomSettings(
+        "Logic.",
+        "com.example.maven-samples",
+        "http://www.example.com/server",
+        Seq(),
+        VersionControl(
+          Some("http://github.com/gabrielf/maven-samples/server"),
+          Some("scm:git:git@github.com:gabrielf/maven-samples.git/server"),
+          Some("scm:git:git@github.com:gabrielf/maven-samples.git/server"),
+          Some("HEAD")
+        ),
+        Seq()
+      )
+
       def pomParentProject = Some(Artifact(
         "com.example.maven-samples",
         "multi-module-parent",
@@ -72,6 +100,20 @@ object `package` extends RootModule with MyModule {
       def compileIvyDeps = super.compileIvyDeps() ++
         Seq(Deps.`javax.servlet.jsp:jsp-api`, Deps.`javax.servlet:servlet-api`)
 
+      def pomSettings = PomSettings(
+        "Webapp.",
+        "com.example.maven-samples",
+        "http://www.example.com/webapp",
+        Seq(),
+        VersionControl(
+          Some("http://github.com/gabrielf/maven-samples/webapp"),
+          Some("scm:git:git@github.com:gabrielf/maven-samples.git/webapp"),
+          Some("scm:git:git@github.com:gabrielf/maven-samples.git/webapp"),
+          Some("HEAD")
+        ),
+        Seq()
+      )
+
       def pomPackagingType = "war"
 
       def pomParentProject = Some(Artifact(
@@ -98,6 +140,20 @@ object `package` extends RootModule with MyModule {
     def ivyDeps = super.ivyDeps() ++
       Seq(Deps.`javax.servlet.jsp:jsp-api`, Deps.`javax.servlet:servlet-api`)
 
+    def pomSettings = PomSettings(
+      "Sample single module Maven project with a working, deployable site.",
+      "com.example.maven-samples",
+      "http://www.example.com",
+      Seq(),
+      VersionControl(
+        Some("http://github.com/gabrielf/maven-samples"),
+        Some("scm:git:git@github.com:gabrielf/maven-samples.git"),
+        Some("scm:git:git@github.com:gabrielf/maven-samples.git"),
+        Some("HEAD")
+      ),
+      Seq()
+    )
+
     def publishProperties = super.publishProperties() ++ Map(
       ("project.build.sourceEncoding", "utf-8"),
       ("project.reporting.outputEncoding", "utf-8")
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index be87963d5cf..c60928b35f8 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -229,21 +229,12 @@ object SbtBuildGenMain
       repositories
     )
 
-    IrBaseInfo(
-      javacOptions,
-      scalaVersion,
-      scalacOptions,
-      repositories,
-      noPom = false, // always publish
-      publishVersion,
-      Seq.empty,
-      typedef
-    )
+    IrBaseInfo(typedef)
   }
 
   override def extractIrBuild(
       cfg: Config,
-      baseInfo: IrBaseInfo,
+      // baseInfo: IrBaseInfo,
       build: Node[Project],
       packages: Map[(String, String, String), String]
   ): IrBuild = {
@@ -257,18 +248,13 @@ object SbtBuildGenMain
       testModuleMainType = "SbtTests",
       hasTest = os.exists(getMillSourcePath(project) / "src/test"),
       dirs = build.dirs,
-      repositories = getRepositories(buildInfo).diff(baseInfo.repositories),
-      javacOptions = getJavacOptions(buildInfo).diff(baseInfo.javacOptions),
-      scalaVersion =
-        if (buildInfo.scalaVersion != baseInfo.scalaVersion) buildInfo.scalaVersion else None,
-      scalacOptions = buildInfo.scalacOptions.map(scalacOptions =>
-        baseInfo.scalacOptions.fold(scalacOptions)(baseScalacOptions =>
-          scalacOptions.diff(baseScalacOptions)
-        )
-      ),
+      repositories = getRepositories(buildInfo),
+      javacOptions = getJavacOptions(buildInfo),
+      scalaVersion = buildInfo.scalaVersion,
+      scalacOptions = buildInfo.scalacOptions,
       projectName = project.name,
-      pomSettings = takeIrPomIfNeeded(baseInfo, extractPomSettings(buildInfo.buildPublicationInfo)),
-      publishVersion = if (version == baseInfo.publishVersion) null else version,
+      pomSettings = extractPomSettings(buildInfo.buildPublicationInfo),
+      publishVersion = version,
       packaging = null, // not available in sbt as it seems
       pomParentArtifact = null, // not available
       resources = Nil,
@@ -305,7 +291,7 @@ object SbtBuildGenMain
       s"coursier.maven.MavenRepository(${escape(resolver.root)})"
     )
 
-  def getPublishVersion(buildInfo: BuildInfo): String =
+  def getPublishVersion(buildInfo: BuildInfo): String | Null =
     buildInfo.buildPublicationInfo.version.orNull
 
   // originally named `ivyInterp` in the Maven and module
diff --git a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
index 8e5e0a141bd..250cbc075e2 100644
--- a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
@@ -79,6 +79,8 @@ object `package` extends RootModule with BaseModule {
 
   object multi1 extends BaseModule {
 
+    def scalacOptions = super.scalacOptions() ++ Seq("-V")
+
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.julien-truffaut:monocle-core`,
@@ -125,6 +127,16 @@ object `package` extends RootModule with BaseModule {
 
   object multi2 extends BaseModule {
 
+    def scalacOptions = Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation"
+    )
+
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.pureconfig:pureconfig`,
diff --git a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
index de6ca5569e5..53453cefe08 100644
--- a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
@@ -81,6 +81,8 @@ object `package` extends RootModule with BaseModule {
 
   object multi1 extends BaseModule {
 
+    def scalacOptions = super.scalacOptions() ++ Seq("-V")
+
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.julien-truffaut:monocle-core`,
@@ -104,6 +106,16 @@ object `package` extends RootModule with BaseModule {
 
   object multi2 extends BaseModule {
 
+    def scalacOptions = Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation"
+    )
+
     def ivyDeps = super.ivyDeps() ++ Seq(
       Deps.`ch.qos.logback:logback-classic`,
       Deps.`com.github.pureconfig:pureconfig`,
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
index ddd1fcbe2b9..a112998394a 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi1/package.mill
@@ -18,7 +18,8 @@ object `package` extends RootModule with SbtModule with PublishModule {
     "-language:postfixOps",
     "-deprecation",
     "-encoding",
-    "utf8"
+    "utf8",
+    "-V"
   )
 
   def repositoriesTask = Task.Anon {
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
index 16bc9ddac87..2432745489e 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/multi2/package.mill
@@ -16,9 +16,7 @@ object `package` extends RootModule with SbtModule with PublishModule {
     "-language:higherKinds",
     "-language:implicitConversions",
     "-language:postfixOps",
-    "-deprecation",
-    "-encoding",
-    "utf8"
+    "-deprecation"
   )
 
   def repositoriesTask = Task.Anon {
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index f6e0ad0168d..a97b9cff956 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -32,7 +32,7 @@ lazy val common = project
 lazy val multi1 = project
   .settings(
     name := "multi1",
-    settings,
+    settings ++ Seq(scalacOptions ++= Seq("-V")),
     assemblySettings,
     libraryDependencies ++= commonDependencies ++ Seq(
       dependencies.monocleCore,
@@ -46,7 +46,15 @@ lazy val multi1 = project
 lazy val multi2 = project
   .settings(
     name := "multi2",
-    settings,
+    settings ++ Seq(scalacOptions := Seq(
+      "-unchecked",
+      "-feature",
+      "-language:existentials",
+      "-language:higherKinds",
+      "-language:implicitConversions",
+      "-language:postfixOps",
+      "-deprecation"
+    )),
     assemblySettings,
     libraryDependencies ++= commonDependencies ++ Seq(
       dependencies.pureconfig

From 34b837d1fec2b135086a481476dfae5805b69d3d Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 11:16:39 +0800
Subject: [PATCH 54/70] Fix assertions in `MillInitSbtMultiProjectExampleTests`
 that fail due to commit 768a2b104f97d0275a47b9e0f4e1f492dec647fd, which is
 uncompleted in commit c819207ff0e8ad7ad81304ba448e07fa00d85629

Somehow this fails in the CI on Linux with JDK 11 but not on my device:

```text
java.lang.AssertionError: assertion failed: task common.test succeeded
```
---
 .../feature/init/src/MillInitSbtTests.scala   | 25 +++++++++++--------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 6d002f52fcb..f2047ab6af6 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -93,13 +93,18 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
       bumpSbtTo1107(tester.workspacePath)
 
       val submodules = Seq("common", "multi1", "multi2")
-
-      tester.testMillInit(
-        // initCommand = defaultInitCommand ++ Seq("--jvm-id", "11"),
-        expectedCompileTasks =
-          Some(if (System.getProperty("java.version").split('.').head.toInt <= 11)
-            SplitResolvedTasks(Seq("compile") ++ submodules.flatMap(_.allCompileTasks), Seq.empty)
-          else {
+      if (System.getProperty("java.version").split('.').head.toInt <= 11)
+        tester.testMillInit(
+          expectedCompileTasks = Some(SplitResolvedTasks(
+            Seq("compile") ++ submodules.flatMap(_.allCompileTasks),
+            Seq.empty
+          )),
+          expectedTestTasks = Some(SplitResolvedTasks(submodules.map(_.testTask), Seq.empty))
+        )
+      else
+        tester.testMillInit(
+          // initCommand = defaultInitCommand ++ Seq("--jvm-id", "11"),
+          expectedCompileTasks = Some({
             /*
             `multi1.compile` doesn't work well when Mill is run with JDK 17 and 21:
             ```text
@@ -109,7 +114,7 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
                 scala.tools.nsc.classpath.JrtClassPath.asURLs(DirectoryClassPath.scala:183)
                 ...
             ```
-            Passing a `jvmId` 11 doesn't work.
+            Passing a `jvmId` 11 doesn't work here.
              */
             val succeededSubmoduleCompileTasks = Seq("common.compile", "multi2.compile")
             SplitResolvedTasks(
@@ -117,8 +122,8 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
               (submodules.flatMap(_.allCompileTasks).toSet -- succeededSubmoduleCompileTasks).toSeq
             )
           }),
-        expectedTestTasks = Some(SplitResolvedTasks(Seq(), submodules.map(_.testTask)))
-      )
+          expectedTestTasks = Some(SplitResolvedTasks(Seq.empty, submodules.map(_.testTask)))
+        )
     }
   }
 }

From 729fc9d619ec4a9d30be6bf2347fb13d310544de Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 11:44:51 +0800
Subject: [PATCH 55/70] Fix bugs introduced in commit
 22033e909dd461689b374815ca4602b087b8830f revealed by
 `MillInitMavenNettyTests` in the integration tests

---
 .../src/mill/main/buildgen/BuildGenUtil.scala         | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index ef415327b16..56e4297f5f8 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -386,12 +386,13 @@ object BuildGenUtil {
       else
         // Note that the super def is called even when it's empty.
         // Some super functions can be called without parentheses, but we just add it here for simplicity.
-        Some(optional(
-          s"super.$defName() ++ Seq",
-          args.iterator.drop(superLength).map(transform)
-        ))
+        Some(args.iterator.drop(superLength).map(transform)
+          .mkString(s"super.$defName() ++ Seq(", ",", ")"))
     } else
-      Some(optional(s"Seq", args.iterator.map(transform)))
+      Some(
+        if (args.isEmpty) "Seq.empty[String]" // The inference type is `Seq[Nothing]` otherwise.
+        else args.iterator.map(transform).mkString("Seq(", ",", ")")
+      )
 
   def renderStringSeqTargetDefWithSuper(
       defName: String,

From f1bfd9a9d9520d41297b87eb3224edce6b894db4 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 11:52:47 +0800
Subject: [PATCH 56/70] Fix some grammar mistakes

---
 main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index 56e4297f5f8..3d14f4a5f32 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -385,12 +385,12 @@ object BuildGenUtil {
       if (args.length == superLength) None
       else
         // Note that the super def is called even when it's empty.
-        // Some super functions can be called without parentheses, but we just add it here for simplicity.
+        // Some super functions can be called without parentheses, but we just add them here for simplicity.
         Some(args.iterator.drop(superLength).map(transform)
           .mkString(s"super.$defName() ++ Seq(", ",", ")"))
     } else
       Some(
-        if (args.isEmpty) "Seq.empty[String]" // The inference type is `Seq[Nothing]` otherwise.
+        if (args.isEmpty) "Seq.empty[String]" // The inferred type is `Seq[Nothing]` otherwise.
         else args.iterator.map(transform).mkString("Seq(", ",", ")")
       )
 

From af5454d96a0bac552c687284f77083100eebe6f0 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 11:59:56 +0800
Subject: [PATCH 57/70] Rename some integration tests for explicitness and
 consistency

---
 integration/feature/init/src/MillInitSbtTests.scala | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index f2047ab6af6..3a2e931e68e 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -10,7 +10,7 @@ def bumpSbtTo1107(workspacePath: os.Path) =
 
 // relatively small libraries
 
-object MillInitLibraryExampleTests extends BuildGenTestSuite {
+object MillInitSbtLibraryExampleTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 21 KB
@@ -27,7 +27,7 @@ object MillInitLibraryExampleTests extends BuildGenTestSuite {
   }
 }
 
-object MillInitScalaCsv200Tests extends BuildGenTestSuite {
+object MillInitSbtScalaCsv200Tests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 34 KB
@@ -47,7 +47,7 @@ object MillInitScalaCsv200Tests extends BuildGenTestSuite {
   }
 }
 
-object MillInitScalaCsv136Tests extends BuildGenTestSuite {
+object MillInitSbtScalaCsv136Tests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 28 KB
@@ -130,7 +130,7 @@ object MillInitSbtMultiProjectExampleTests extends BuildGenTestSuite {
 
 // relatively large libraries
 
-object MillInitZioHttpTests extends BuildGenTestSuite {
+object MillInitSbtZioHttpTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
     - 1.4 MB

From 87940401beec8fb61cc730a64d6f352306057f85 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 12:38:44 +0800
Subject: [PATCH 58/70] Update `MillInitSbtZioHttpTests` with the result and
 improve `testAllResolvedTasks` in the meantime

---
 .../init/src/IntegrationTesterExt.scala       | 12 ++---
 .../feature/init/src/MillInitSbtTests.scala   | 45 +++++++++++--------
 2 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/integration/feature/init/src/IntegrationTesterExt.scala b/integration/feature/init/src/IntegrationTesterExt.scala
index 76ef0a77371..e0a71cc0bcb 100644
--- a/integration/feature/init/src/IntegrationTesterExt.scala
+++ b/integration/feature/init/src/IntegrationTesterExt.scala
@@ -7,7 +7,7 @@ val defaultInitCommand =
   Seq("init", "--base-module", "BaseModule", "--deps-object", "Deps", "--merge")
 
 case class SplitResolvedTasks(successful: Seq[String], failed: Seq[String]) {
-  val all = (successful ++ failed).toSet
+  val all = (successful ++ failed).sorted
 }
 
 extension (tester: IntegrationTester)
@@ -39,10 +39,13 @@ extension (tester: IntegrationTester)
         assert(!resolveAllTasksResult.isSuccess)
       )(expected => {
         assert(resolveAllTasksResult.isSuccess)
-        val resolvedAllTasks = resolveAllTasksResult.out.linesIterator.toSet
+        val resolvedAllTasks = resolveAllTasksResult.out.linesIterator.toSeq.sorted
         Predef.assert(
           expected.all == resolvedAllTasks,
-          "expected: " + expected.all + ", resolved: " + resolvedAllTasks
+          s"""
+             |expected: ${expected.all}
+             |resolved: $resolvedAllTasks
+             |""".stripMargin
         )
 
         for (task <- expected.successful)
@@ -72,7 +75,4 @@ extension (module: String) {
     testModule.testTask
   def allCompileTasks: Seq[String] =
     Seq(compileTask, testCompileTask)
-  // TODO This seems not needed.
-  def allTestTasks: Seq[String] =
-    Seq(testTask, testTestTask)
 }
diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 3a2e931e68e..059dca51e98 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -141,30 +141,37 @@ object MillInitSbtZioHttpTests extends BuildGenTestSuite {
     test - integrationTest(url) { tester =>
       bumpSbtTo1107(tester.workspacePath)
 
-      Seq(
-        "sbt-zio-http-grpc-tests",
-        "sbt-zio-http-grpc",
-        "zio-http-benchmarks.compile",
-        "zio-http-cli",
-        "zio-http-docs",
-        "zio-http-example",
-        "zio-http-gen",
-        "zio-http-htmx",
-        "zio-http-testkit",
-        "zio-http-tools",
-        "zio-http.js",
-        "zio-http.jvm"
-      )
+      object submodules {
+        val withTests = Seq(
+          "sbt-zio-http-grpc-tests",
+          "zio-http-cli",
+          "zio-http-gen",
+          "zio-http-htmx",
+          "zio-http-testkit",
+          "zio-http.js",
+          "zio-http.jvm"
+        )
+        val withoutTests = Seq(
+          "sbt-zio-http-grpc",
+          "zio-http-benchmarks",
+          "zio-http-docs",
+          "zio-http-example",
+          "zio-http-tools"
+        )
+      }
 
-      // TODO
-      /*
       // probably due to inheriting `MavenTests` instead of `SbtTests`
       // Some dependencies with currently unsupported `CrossVersion` `For3Use2_13` are not imported properly
       tester.testMillInit(
-        expectedCompileTasks = Some(SplitResolvedTasks(Seq("compile"), submodules.flatMap(_.allCompileTasks))),
-        expectedTestTasks = Some(SplitResolvedTasks(Seq(), submodules.flatMap(_.allTestTasks)))
+        expectedCompileTasks =
+          Some(SplitResolvedTasks(
+            Seq("compile"),
+            submodules.withTests.flatMap(_.allCompileTasks) ++
+              submodules.withoutTests.map(_.compileTask)
+          )),
+        expectedTestTasks =
+          Some(SplitResolvedTasks(Seq(), submodules.withTests.map(_.testTask)))
       )
-       */
     }
   }
 }

From ca1c82766b8325e3f50312e70a184e6b499461d6 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 15:36:47 +0800
Subject: [PATCH 59/70] Support more `CrossVersion` types

- Reformat `ExportBuildPlugin.scala` BTW.
- The existing unit tests and integration tests pass as tested on my device.
---
 .../sbt/models/src/mill/main/sbt/Models.scala | 28 ++++++++++-
 .../mill/main/sbt/ExportBuildPlugin.scala     | 50 +++++++++++--------
 .../src/mill/main/sbt/SbtBuildGenMain.scala   |  8 ++-
 3 files changed, 62 insertions(+), 24 deletions(-)

diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 9fb9d7e8812..1963334175e 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -131,7 +131,7 @@ object Project {
 case class Dependency(
     organization: String, // `groupId` in Maven
     name: String, // `artifactId` in Maven
-    crossVersion: Boolean = false, // TODO support `CrossVersion` types other than binary?
+    crossVersion: CrossVersion = CrossVersion.Disabled,
     revision: String,
     configurations: Option[String]
     // BOM seems not supported by sbt. See https://stackoverflow.com/questions/42032303/how-do-i-use-a-maven-bom-bill-of-materials-to-manage-my-dependencies-in-sbt.
@@ -140,3 +140,29 @@ case class Dependency(
 object Dependency {
   implicit val rw: RW[Dependency] = macroRW
 }
+
+/**
+ * @see [[sbt.librarymanagement.CrossVersion]]
+ */
+sealed trait CrossVersion
+object CrossVersion {
+  case object Disabled extends CrossVersion {
+    implicit val rw: RW[Disabled.type] = macroRW
+  }
+  case object Binary extends CrossVersion {
+    implicit val rw: RW[Binary.type] = macroRW
+  }
+  case object Full extends CrossVersion {
+    implicit val rw: RW[Full.type] = macroRW
+  }
+
+  /**
+   * Including the cases [[sbt.librarymanagement.Constant]], [[sbt.librarymanagement.For2_13Use3]], and [[sbt.librarymanagement.For3Use2_13]].
+   */
+  case class Constant(value: String) extends CrossVersion
+  object Constant {
+    implicit val rw: RW[Constant] = macroRW
+  }
+
+  implicit val rw: RW[CrossVersion] = macroRW
+}
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index bc16baea4c9..a6c26ffc796 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -2,8 +2,8 @@ package mill.main.sbt
 
 import sbt.Keys.*
 import sbt.io.IO
-import sbt.librarymanagement.Disabled
-import sbt.{Def, Developer as _, Project as _, Resolver as _, ScmInfo as _, *}
+import sbt.librarymanagement.{Constant, Disabled, For2_13Use3, For3Use2_13}
+import sbt.{Def, CrossVersion as _, Developer as _, Project as _, Resolver as _, ScmInfo as _, *}
 import upickle.default.*
 
 import java.io.File
@@ -18,7 +18,8 @@ object ExportBuildPlugin extends AutoPlugin {
       "get the `mill.main.sbt.BuildInfo` model of this build or this project"
     )
     // not used anymore
-    val millInitAllDependencies = taskKey[Seq[Dependency]]("get the all the `mill.main.sbt.Dependency`s of this project")
+    val millInitAllDependencies =
+      taskKey[Seq[Dependency]]("get the all the `mill.main.sbt.Dependency`s of this project")
     val millInitProject = taskKey[Project]("get the `mill.main.sbt.Project` model of this project")
     val millInitExportBuild = taskKey[File]("export the build in a JSON file for `mill init`")
   }
@@ -33,8 +34,8 @@ object ExportBuildPlugin extends AutoPlugin {
         (name, url.toExternalForm)
       }),
       organization.?.value,
-      //organizationName.?.value, // not needed
-      //organizationHomepage.?.value.map(_.map(_.toExternalForm)), // not needed
+      // organizationName.?.value, // not needed
+      // organizationHomepage.?.value.map(_.map(_.toExternalForm)), // not needed
       developers.?.value.map(_.map(developer =>
         Developer(developer.id, developer.name, developer.email, developer.url.toExternalForm)
       )),
@@ -62,10 +63,10 @@ object ExportBuildPlugin extends AutoPlugin {
     buildInfoSetting,
     millInitProject :=
       Project(
-        //organization.value,
+        // organization.value,
         name.value,
-        //version.value,
-        //baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
+        // version.value,
+        // baseDirectory.value.relativeTo((ThisBuild / baseDirectory).value).get.getPath.split(File.separator),
         baseDirectory.value.getPath,
         /*{
           // keep the project `BuildInfo` members only when they are different
@@ -95,20 +96,25 @@ object ExportBuildPlugin extends AutoPlugin {
         millInitBuildInfo.value,
 
         /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
-        /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map { moduleID =>
-          Dependency(
-            moduleID.organization,
-            moduleID.name,
-            moduleID.crossVersion match {
-              case Disabled => false
-              case _: Binary => true
-              case crossVersion =>
-                println(s"Dependency $moduleID with unsupported `CrossVersion`: $crossVersion")
-                false
-            },
-            moduleID.revision,
-            moduleID.configurations
-          )
+        /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map {
+          moduleID =>
+            Dependency(
+              moduleID.organization,
+              moduleID.name,
+              moduleID.crossVersion match {
+                case Disabled => CrossVersion.Disabled
+                case _: Binary => CrossVersion.Binary
+                case _: Full => CrossVersion.Full
+                case _: For3Use2_13 => CrossVersion.Constant("2.13")
+                case _: For2_13Use3 => CrossVersion.Constant("3")
+                case constant: Constant => CrossVersion.Constant(constant.value)
+                case crossVersion =>
+                  println(s"Dependency $moduleID with unsupported `CrossVersion`: $crossVersion")
+                  CrossVersion.Disabled
+              },
+              moduleID.revision,
+              moduleID.configurations
+            )
         }
       ),
     // `target.value` doesn't work in `globalSettings` and `buildSettings`, so this is added to `projectSettings.
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index c60928b35f8..7b63b19c8bd 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -302,7 +302,13 @@ object SbtBuildGenMain
      which is a `Vector` of `sbt.librarymanagement.Artifact` and `sbt.librarymanagement.InclExclRule`s.
      */
     import dependency.*
-    s"ivy\"$organization${if (crossVersion) "::" else ":"}$name:$revision\""
+    s"ivy\"$organization${
+        crossVersion match
+          case CrossVersion.Disabled => s":$name"
+          case CrossVersion.Binary => s"::$name"
+          case CrossVersion.Full => s":::$name"
+          case CrossVersion.Constant(value) => s":${name}_$value"
+      }:$revision\""
   }
 
   def extractPomSettings(buildPublicationInfo: BuildPublicationInfo): IrPom = {

From 1cd32b0658f6d353d7a4a976ac44ca935800dc9e Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 15:43:29 +0800
Subject: [PATCH 60/70] Fix a warning discovered by CI `lint-autofix`

---
 main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index ef79db544c0..a5a382f8f1f 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -86,7 +86,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
       pomSettings,
       publishVersion,
       publishProperties,
-      getRepositories(model)
+      repositories
     )
 
     IrBaseInfo(typedef)

From d34d38583439272aa153aa0f26f60f1d70c9890d Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Mon, 24 Feb 2025 15:44:49 +0800
Subject: [PATCH 61/70] Fix a warning by making a def private

---
 main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index 7b63b19c8bd..d6b05c0513e 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -195,7 +195,7 @@ object SbtBuildGenMain
   ): Tree[Node[Option[Project]]] =
     input._2
 
-  def sbtSupertypes = Seq("SbtModule", "PublishModule") // always publish
+  private def sbtSupertypes = Seq("SbtModule", "PublishModule") // always publish
 
   def getBaseInfo(
       input: (BuildInfo, Tree[Node[Option[Project]]]),

From 1d8011cec7464e1dc87136e29ca4ed8c07fa0451 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Tue, 25 Feb 2025 03:34:09 +0800
Subject: [PATCH 62/70] Supported converting `type, `classifier`, and
 `exclusions` in sbt dependencies

- Fix a bug that the custom `RuntimeException` is not thrown "main/init/package.mill" after the code is refactored to use OS-Lib.
- Update unit test code to test the changes and the expected snapshots in test resources correspondingly.
- The existing unit tests and integration tests pass as tested on my device.
- Remove a redundant import `scala.language.higherKinds` in `ExportBuildPlugin.scala`.
---
 .../src/mill/main/buildgen/BuildGenUtil.scala | 18 ++++++++---
 .../mill/main/gradle/GradleBuildGenMain.scala |  2 +-
 .../mill/main/maven/MavenBuildGenMain.scala   |  1 +
 main/init/package.mill                        | 17 +++++++----
 .../sbt/models/src/mill/main/sbt/Models.scala |  5 +++-
 .../mill/main/sbt/ExportBuildPlugin.scala     | 30 +++++++++++++++----
 .../src/mill/main/sbt/SbtBuildGenMain.scala   | 27 +++++++++--------
 .../all/sbt-multi-project-example/build.mill  |  6 ++++
 .../sbt-multi-project-example/build.mill      | 10 ++++++-
 .../nested/nested/package.mill                |  4 +++
 .../sbt-multi-project-example/build.sbt       |  5 ++++
 11 files changed, 94 insertions(+), 31 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
index 3d14f4a5f32..f8319e51e32 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenUtil.scala
@@ -11,6 +11,7 @@ import mill.constants.CodeGenConstants.{
 import mill.constants.OutFiles
 import mill.main.buildgen.BuildObject.Companions
 import mill.runner.FileImportGraph.backtickWrap
+import mill.scalalib.CrossVersion
 
 import scala.collection.immutable.SortedSet
 import scala.util.boundary
@@ -287,11 +288,20 @@ object BuildGenUtil {
   def renderIvyString(
       group: String,
       artifact: String,
-      version: String = null,
-      tpe: String = null,
-      classifier: String = null,
+      crossVersion: Option[CrossVersion] = None,
+      version: String | Null = null,
+      tpe: String | Null = null,
+      classifier: String | Null = null,
       excludes: IterableOnce[(String, String)] = Seq.empty
   ): String = {
+    val sepArtifact = crossVersion match {
+      case None => s":$artifact"
+      case Some(value) => value match {
+          case CrossVersion.Constant(value, _) => s":${artifact}_$value"
+          case CrossVersion.Binary(_) => s"::$artifact"
+          case CrossVersion.Full(_) => s":::$artifact"
+        }
+    }
     val sepVersion =
       if (null == version) {
         println(
@@ -314,7 +324,7 @@ object BuildGenUtil {
       .map { case (group, artifact) => s";exclude=$group:$artifact" }
       .mkString
 
-    s"ivy\"$group:$artifact$sepVersion$sepTpe$sepClassifier$sepExcludes\""
+    s"ivy\"$group$sepArtifact$sepVersion$sepTpe$sepClassifier$sepExcludes\""
   }
 
   def isBom(groupArtifactVersion: (String, String, String)): Boolean =
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index da0620bba53..b9c72425c1d 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -243,7 +243,7 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     }
 
   def interpIvy(dep: JavaModel.Dep): String = {
-    BuildGenUtil.renderIvyString(dep.group(), dep.name(), dep.version())
+    BuildGenUtil.renderIvyString(dep.group(), dep.name(), version = dep.version())
   }
 
   def extractPomSettings(project: ProjectModel): IrPom | Null = {
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index a5a382f8f1f..e5ceb32c4bf 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -173,6 +173,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
     BuildGenUtil.renderIvyString(
       dep.getGroupId,
       dep.getArtifactId,
+      None,
       dep.getVersion,
       dep.getType,
       dep.getClassifier,
diff --git a/main/init/package.mill b/main/init/package.mill
index 716171fc646..65b11006c4d 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -109,19 +109,24 @@ object `package` extends RootModule with build.MillPublishScalaModule {
 
       val isWindows = System.getProperty("os.name").toLowerCase.startsWith("windows")
       val version = build.millVersion()
-      if (
+
+      try {
         os.call(
           // The version is passed to the sbt build so it correctly resolves the "models" dependency version and sets its own version.
           if (isWindows) ("sbt.bat", s"""set version := \\"$version\\"""", "assembly")
           else ("sbt", s"""set version := "$version"""", "assembly"),
           cwd = sbtPluginProjectPath,
           stdout = os.Inherit
-        ).exitCode != 0
-      )
-        throw new RuntimeException(
-          "Failed to run `sbt assembly` in the \"sbt-mill-init-export-build\" sbt project. " +
-            "Check if the project builds correctly and if you have sbt available on your system, and install it if you don't."
         )
+      } catch {
+        case e: os.SubprocessException =>
+          throw new RuntimeException(
+            "Failed to run `sbt assembly` in the \"sbt-mill-init-export-build\" sbt project. " +
+              "Check if the project builds correctly and if you have sbt available on your system, and install it if you don't.",
+            e
+          )
+        case t : Throwable => throw t
+      }
 
       os.copy(
         sbtPluginProjectPath / "target" / "scala-2.12" / "sbt-1.0" / s"sbt-mill-init-export-build-assembly-$version.jar",
diff --git a/main/init/sbt/models/src/mill/main/sbt/Models.scala b/main/init/sbt/models/src/mill/main/sbt/Models.scala
index 1963334175e..b813dd88fc7 100644
--- a/main/init/sbt/models/src/mill/main/sbt/Models.scala
+++ b/main/init/sbt/models/src/mill/main/sbt/Models.scala
@@ -133,9 +133,12 @@ case class Dependency(
     name: String, // `artifactId` in Maven
     crossVersion: CrossVersion = CrossVersion.Disabled,
     revision: String,
-    configurations: Option[String]
+    configurations: Option[String],
     // BOM seems not supported by sbt. See https://stackoverflow.com/questions/42032303/how-do-i-use-a-maven-bom-bill-of-materials-to-manage-my-dependencies-in-sbt.
     // isBom : Boolean = false
+    tpe: Option[String],
+    classifier: Option[String],
+    excludes: Seq[(String, String)]
 )
 object Dependency {
   implicit val rw: RW[Dependency] = macroRW
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index a6c26ffc796..270fcebcefa 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -7,7 +7,6 @@ import sbt.{Def, CrossVersion as _, Developer as _, Project as _, Resolver as _,
 import upickle.default.*
 
 import java.io.File
-import scala.language.higherKinds
 
 object ExportBuildPlugin extends AutoPlugin {
   override def trigger = allRequirements
@@ -96,9 +95,9 @@ object ExportBuildPlugin extends AutoPlugin {
         millInitBuildInfo.value,
 
         /** See the TODO in [[sbt.Defaults]] above `allDependencies :=` for more details (v1.10.7, Lines 3210 - 3212). */
-        /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).map {
-          moduleID =>
-            Dependency(
+        /*allDependencies.value*/ (projectDependencies.value ++ libraryDependencies.value).flatMap(
+          moduleID => {
+            val dependency = Dependency(
               moduleID.organization,
               moduleID.name,
               moduleID.crossVersion match {
@@ -113,9 +112,28 @@ object ExportBuildPlugin extends AutoPlugin {
                   CrossVersion.Disabled
               },
               moduleID.revision,
-              moduleID.configurations
+              moduleID.configurations,
+              None,
+              None,
+              moduleID.exclusions.map(inclExclRule =>
+                (inclExclRule.organization, inclExclRule.name)
+              )
             )
-        }
+            val explicitArtifacts = moduleID.explicitArtifacts
+            if (explicitArtifacts.isEmpty)
+              Seq(dependency)
+            else
+              explicitArtifacts.map(artifact =>
+                dependency.copy(
+                  tpe = Some(artifact.`type`) /*{
+                    val tpe = artifact.`type`
+                    Option.when(tpe != DefaultType)(tpe)
+                  }*/,
+                  classifier = artifact.classifier
+                )
+              )
+          }
+        )
       ),
     // `target.value` doesn't work in `globalSettings` and `buildSettings`, so this is added to `projectSettings.
     millInitExportBuild := {
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index d6b05c0513e..ed811d6be62 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -5,6 +5,7 @@ import mill.constants.Util
 import mill.main.buildgen.*
 import mill.main.buildgen.BuildGenUtil.*
 import mill.main.buildgen.IrDependencyType.*
+import mill.scalalib.CrossVersion as MillCrossVersion
 import os.Path
 
 import scala.collection.MapView
@@ -296,19 +297,21 @@ object SbtBuildGenMain
 
   // originally named `ivyInterp` in the Maven and module
   def renderIvy(dependency: Dependency): String = {
-    /*
-    TODO `type, `classifier`, and `exclusions` are not processed yet.
-     Processing them involves extracting information from `ModuleID.explicitArtifacts`
-     which is a `Vector` of `sbt.librarymanagement.Artifact` and `sbt.librarymanagement.InclExclRule`s.
-     */
     import dependency.*
-    s"ivy\"$organization${
-        crossVersion match
-          case CrossVersion.Disabled => s":$name"
-          case CrossVersion.Binary => s"::$name"
-          case CrossVersion.Full => s":::$name"
-          case CrossVersion.Constant(value) => s":${name}_$value"
-      }:$revision\""
+    renderIvyString(
+      organization,
+      name,
+      crossVersion match {
+        case CrossVersion.Disabled => None
+        case CrossVersion.Binary => Some(MillCrossVersion.Binary(false))
+        case CrossVersion.Full => Some(MillCrossVersion.Full(false))
+        case CrossVersion.Constant(value) => Some(MillCrossVersion.Constant(value, false))
+      },
+      version = revision,
+      tpe = tpe.orNull,
+      classifier = classifier.orNull,
+      excludes = excludes
+    )
   }
 
   def extractPomSettings(buildPublicationInfo: BuildPublicationInfo): IrPom = {
diff --git a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
index 250cbc075e2..82875313c59 100644
--- a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
@@ -26,6 +26,9 @@ object Deps {
     ivy"com.typesafe.scala-logging::scala-logging:3.7.2"
   val `com.typesafe:config` = ivy"com.typesafe:config:1.3.1"
 
+  val `io.netty:netty-transport-native-epoll` =
+    ivy"io.netty:netty-transport-native-epoll:4.1.118.Final;type=pom;classifier=linux-x86_64;exclude=io.netty:netty-transport-native-epoll"
+
   val `net.logstash.logback:logstash-logback-encoder` =
     ivy"net.logstash.logback:logstash-logback-encoder:4.11"
   val `org.scalacheck:scalacheck` = ivy"org.scalacheck::scalacheck:1.13.5"
@@ -184,6 +187,9 @@ object `package` extends RootModule with BaseModule {
 
     object nested extends BaseModule {
 
+      def ivyDeps = super.ivyDeps() ++
+        Seq(Deps.`io.netty:netty-transport-native-epoll`)
+
       def pomSettings = PomSettings(
         "This is an sbt sample project for testing Mill's init command.",
         "com.pbassiner",
diff --git a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
index 53453cefe08..bdae91e9065 100644
--- a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
@@ -26,6 +26,9 @@ object Deps {
     ivy"com.typesafe.scala-logging::scala-logging:3.7.2"
   val `com.typesafe:config` = ivy"com.typesafe:config:1.3.1"
 
+  val `io.netty:netty-transport-native-epoll` =
+    ivy"io.netty:netty-transport-native-epoll:4.1.118.Final;type=pom;classifier=linux-x86_64;exclude=io.netty:netty-transport-native-epoll"
+
   val `net.logstash.logback:logstash-logback-encoder` =
     ivy"net.logstash.logback:logstash-logback-encoder:4.11"
   val `org.scalacheck:scalacheck` = ivy"org.scalacheck::scalacheck:1.13.5"
@@ -138,7 +141,12 @@ object `package` extends RootModule with BaseModule {
 
   object nested extends Module {
 
-    object nested extends BaseModule {}
+    object nested extends BaseModule {
+
+      def ivyDeps = super.ivyDeps() ++
+        Seq(Deps.`io.netty:netty-transport-native-epoll`)
+
+    }
   }
 }
 
diff --git a/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
index e4c9672c52f..2459deec0e2 100644
--- a/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
+++ b/main/init/sbt/test/resources/expected/sbt-multi-project-example/nested/nested/package.mill
@@ -32,6 +32,10 @@ object `package` extends RootModule with SbtModule with PublishModule {
     )
   }
 
+  def ivyDeps = super.ivyDeps() ++ Seq(
+    ivy"io.netty:netty-transport-native-epoll:4.1.118.Final;type=pom;classifier=linux-x86_64;exclude=io.netty:netty-transport-native-epoll"
+  )
+
   def pomSettings = PomSettings(
     "This is an sbt sample project for testing Mill's init command.",
     "com.pbassiner",
diff --git a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
index a97b9cff956..b9fe3451faa 100644
--- a/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
+++ b/main/init/sbt/test/resources/sbt-multi-project-example/build.sbt
@@ -66,6 +66,11 @@ lazy val multi2 = project
 
 lazy val nested = project
   .in(file("nested/nested"))
+  .settings(
+    libraryDependencies += ("io.netty" % "netty-transport-native-epoll" % "4.1.118.Final")
+      .artifacts(Artifact("netty-transport-native-epoll").withType("pom").withClassifier(Some("linux-x86_64")))
+      .exclude("io.netty", "netty-transport-native-epoll")
+  )
 
 // DEPENDENCIES
 

From 12e9d734c11f59cf673eaf5eef0a482e55efcb82 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Tue, 25 Feb 2025 11:16:10 +0800
Subject: [PATCH 63/70] Run more `compile` and `test` tasks in the submodules
 of all the converted builds in the integration tests

This completes commit 88c31b18e667274563ca953ef7442d877ef2a129.

Add `millInitExportBuild / aggregate := false` in `ExportBuildPlugin` to prevent the `millInitExportBuild` sbt task run in every child project, which seems to have sped up the tests.
---
 .../feature/init/src/MillInitSbtTests.scala   | 78 +++++++++++++++----
 .../mill/main/sbt/ExportBuildPlugin.scala     |  3 +-
 2 files changed, 63 insertions(+), 18 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 059dca51e98..9e1ab62b175 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -4,12 +4,14 @@ import mill.constants.Util
 import mill.integration.testMillInit
 import utest.*
 
-def bumpSbtTo1107(workspacePath: os.Path) =
+private def bumpSbtTo1107(workspacePath: os.Path) =
   // bump sbt version to resolve compatibility issues with lower sbt versions and higher JDK versions
   os.write.over(workspacePath / "project" / "build.properties", "sbt.version = 1.10.7")
 
 // relatively small libraries
 
+private val scalaPlatforms = Seq("js", "jvm", "native")
+
 object MillInitSbtLibraryExampleTests extends BuildGenTestSuite {
   def tests: Tests = Tests {
     /*
@@ -160,8 +162,7 @@ object MillInitSbtZioHttpTests extends BuildGenTestSuite {
         )
       }
 
-      // probably due to inheriting `MavenTests` instead of `SbtTests`
-      // Some dependencies with currently unsupported `CrossVersion` `For3Use2_13` are not imported properly
+      // The sources in "zio-http/shared" in cross-builds are not supported in conversion yet, causing all dependent project's `compile` tasks to file.
       tester.testMillInit(
         expectedCompileTasks =
           Some(SplitResolvedTasks(
@@ -191,15 +192,27 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
       if (!Util.isWindows)
         os.call(("chmod", "+x", "sbt"), cwd = workspacePath)
 
-      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
-
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
+      val crossDirs = Seq("core", "effect", "example", "iteratee", "scalacheck-binding", "tests")
+      val crossSubmodules = crossDirs.flatMap(dir => scalaPlatforms.map(name => s"$dir.$name"))
+      val rootModules = Seq("rootJS", "rootJVM", "rootNative")
 
-      // TODO
-      val resolveCompilesResult = eval(("resolve", "__.compile"))
-      println("Resolve result: " + resolveCompilesResult.out)
+      tester.testMillInit(
+        expectedCompileTasks =
+          Some(SplitResolvedTasks(
+            /*
+            These modules are converted from sbt's aggregated projects without sources or dependencies,
+            therefore, their no-op `compile` tasks succeed.
+             */
+            Seq("compile") ++ rootModules.map(_.compileTask),
+            /*
+            Common sources in directories such as "core/src" are defined as projects in and therefore not converted,
+            therefore, the tasks in modules such as "core/jvm" as common definitions are not found.
+             */
+            crossSubmodules.map(_.compileTask)
+          )),
+        // Scalaz uses ScalaCheck which is not supported in conversion yet.
+        expectedTestTasks = None
+      )
     }
   }
 }
@@ -215,13 +228,44 @@ object MillInitSbtCatsTests extends BuildGenTestSuite {
     val url = "https://github.com/typelevel/cats/archive/refs/tags/v2.13.0.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
-
-      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
+      val sbtCrossProjects = Seq(
+        "algebra-laws",
+        "alleycats-laws",
+        "kernel-laws",
+        "tests"
+      )
+      /*
+      These sbt cross projects have `CrossType.Pure` set,
+      so there platform projects have directories named ".js", ".jvm", and ".native",
+      and such modules starting with "." are not properly recognized by Mill
+       */
+      val sbtCrossProjectsWithCrossTypePure =
+        Seq("algebra-core", "alleycats-core", "core", "free", "kernel", "laws", "testkit")
+
+      assert((sbtCrossProjects intersect sbtCrossProjectsWithCrossTypePure).isEmpty)
+
+      val nonCrossModules = Seq("bench", "binCompatTest", "site", "unidocs")
+      val resolvedTestModules = (scalaPlatforms.map(name => s"alleycats-laws.$name") ++
+        Seq("binCompatTest", "tests.js"))
+        .map(module => s"$module.test")
+      val submoduleCompileTasks = (sbtCrossProjects.flatMap(project =>
+        scalaPlatforms.map(platform => s"$project.$platform")
+      ) ++
+        nonCrossModules ++
+        resolvedTestModules)
+        .map(module => s"$module.compile")
 
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
+      tester.testMillInit(
+        expectedCompileTasks = Some({
+          val succeededSubmoduleCompileTasks =
+            Seq("tests.js.compile", "tests.jvm.compile", "unidocs.compile")
+          SplitResolvedTasks(
+            Seq("compile") ++ succeededSubmoduleCompileTasks,
+            submoduleCompileTasks diff succeededSubmoduleCompileTasks
+          )
+        }),
+        expectedTestTasks = Some(SplitResolvedTasks(Seq(), resolvedTestModules))
+      )
     }
   }
 }
diff --git a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
index 270fcebcefa..fdc4b56ec31 100644
--- a/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
+++ b/main/init/sbt/sbt-mill-init-export-build/src/main/scala/mill/main/sbt/ExportBuildPlugin.scala
@@ -144,6 +144,7 @@ object ExportBuildPlugin extends AutoPlugin {
       val outputFile = target.value / "mill-init-build-export.json"
       IO.write(outputFile, write(buildExport))
       outputFile
-    }
+    },
+    millInitExportBuild / aggregate := false
   )
 }

From 2be0d803fbeec14ef38f638babb05e9a7a1f350b Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Tue, 25 Feb 2025 23:38:35 +0800
Subject: [PATCH 64/70] Reformat "main/init/package.mill" as `lint-autofix`
 fails on CI

---
 main/init/package.mill | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/main/init/package.mill b/main/init/package.mill
index 65b11006c4d..c895eda7b10 100644
--- a/main/init/package.mill
+++ b/main/init/package.mill
@@ -125,7 +125,7 @@ object `package` extends RootModule with build.MillPublishScalaModule {
               "Check if the project builds correctly and if you have sbt available on your system, and install it if you don't.",
             e
           )
-        case t : Throwable => throw t
+        case t: Throwable => throw t
       }
 
       os.copy(

From 44c7381189454a35ed83040c8dc83e03edaa7297 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 01:56:21 +0800
Subject: [PATCH 65/70] Add a comment

---
 integration/feature/init/src/MillInitSbtTests.scala | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 9e1ab62b175..64646b2d683 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -246,7 +246,11 @@ object MillInitSbtCatsTests extends BuildGenTestSuite {
 
       val nonCrossModules = Seq("bench", "binCompatTest", "site", "unidocs")
       val resolvedTestModules = (scalaPlatforms.map(name => s"alleycats-laws.$name") ++
-        Seq("binCompatTest", "tests.js"))
+        Seq(
+          "binCompatTest",
+          // "tests.jvm" and "tests.native" don't have their own test sources, so their test modules are not converted.
+          "tests.js"
+        ))
         .map(module => s"$module.test")
       val submoduleCompileTasks = (sbtCrossProjects.flatMap(project =>
         scalaPlatforms.map(platform => s"$project.$platform")

From 8ca434a656e42ff3cfaaf50fd66b328d266a99ce Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 03:00:22 +0800
Subject: [PATCH 66/70] Review the reasons why the tasks succeed or fail and
 improve comments in `MillInitSbtTests.scala`

---
 integration/feature/init/src/MillInitSbtTests.scala | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 64646b2d683..88f5bbea36d 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -68,7 +68,7 @@ object MillInitSbtScalaCsv136Tests extends BuildGenTestSuite {
         expectedTestTasks = Some(SplitResolvedTasks(
           Seq(),
           /*
-          Relative paths to the workspace are used in the test sources such as `new File("src/test/resources/simple.csv")`
+          Paths relative to the workspace are used in the test sources such as `new File("src/test/resources/simple.csv")`
           and they seem to cause the test to fail with Mill:
           ```text
           java.io.FileNotFoundException: src/test/resources/simple.csv (No such file or directory)
@@ -162,7 +162,11 @@ object MillInitSbtZioHttpTests extends BuildGenTestSuite {
         )
       }
 
-      // The sources in "zio-http/shared" in cross-builds are not supported in conversion yet, causing all dependent project's `compile` tasks to file.
+      /*
+      The sources shared among multiple platforms (JVM and Scala.js) in "zio-http/shared" in cross-builds
+      are not supported in conversion yet,
+      causing all dependent project's `compile` tasks to fail.
+       */
       tester.testMillInit(
         expectedCompileTasks =
           Some(SplitResolvedTasks(
@@ -205,8 +209,9 @@ object MillInitSbtScalazTests extends BuildGenTestSuite {
              */
             Seq("compile") ++ rootModules.map(_.compileTask),
             /*
-            Common sources in directories such as "core/src" are defined as projects in and therefore not converted,
-            therefore, the tasks in modules such as "core/jvm" as common definitions are not found.
+            Common sources shared among multiple platforms (JVM, Scala.js, and Scala Native) in directories such as "core/src"
+            are not defined as sbt projects and therefore not converted.
+            This leads to modules such as "core/jvm" not compiling as common definitions are not found.
              */
             crossSubmodules.map(_.compileTask)
           )),

From 75af776d2eaddd6b13a21aafe38a28ae7ba457f0 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 03:22:26 +0800
Subject: [PATCH 67/70] Run more `compile` and `test` tasks in
 `MillInitSbtScalaCheckTests`

---
 .../feature/init/src/MillInitSbtTests.scala   | 21 ++++++++++++-------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/integration/feature/init/src/MillInitSbtTests.scala b/integration/feature/init/src/MillInitSbtTests.scala
index 88f5bbea36d..b6ec4fe4cdb 100644
--- a/integration/feature/init/src/MillInitSbtTests.scala
+++ b/integration/feature/init/src/MillInitSbtTests.scala
@@ -313,15 +313,20 @@ object MillInitSbtScalaCheckTests extends BuildGenTestSuite {
     val url = "https://github.com/typelevel/scalacheck/archive/refs/tags/v1.18.1.zip"
 
     test - integrationTest(url) { tester =>
-      import tester.*
-
-      bumpSbtTo1107(workspacePath)
-
-      val initResult = eval(defaultInitCommand, stdout = os.Inherit, stderr = os.Inherit)
-      assert(initResult.isSuccess)
+      bumpSbtTo1107(tester.workspacePath)
 
-      val compileResult = eval("compile")
-      assert(compileResult.isSuccess)
+      /*
+      The sources shared among multiple platforms (JVM, Scala.js, and Scala Native) in "core/shared" in cross-builds
+      are not supported in conversion yet,
+      causing all dependent project's `compile` tasks to fail.
+       */
+      val submodules = scalaPlatforms.map(platform => s"core.$platform") :+ "bench"
+      tester.testMillInit(
+        expectedCompileTasks =
+          Some(SplitResolvedTasks(Seq("compile"), submodules.map(_.compileTask))),
+        // ScalaCheck itself as a test framework is not supported in conversion yet.
+        expectedTestTasks = None
+      )
     }
   }
 }

From c2256f8af08b369e8aed15299fd0425e0a0f4ec3 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 03:51:26 +0800
Subject: [PATCH 68/70] Reformat

---
 .../gradle/src/mill/main/gradle/GradleBuildGenMain.scala    | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index 1977da79437..bc83b1def07 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -198,7 +198,11 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
 
   def getMillSourcePath(project: ProjectModel): Path = os.Path(project.directory())
 
-  override def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[ProjectModel]): Seq[String] =
+  override def getSupertypes(
+      cfg: Config,
+      baseInfo: IrBaseInfo,
+      build: Node[ProjectModel]
+  ): Seq[String] =
     Seq("RootModule") ++
       Option.when(null != build.value.maven().pom() && {
         val baseTrait = baseInfo.moduleTypedef

From 10d2076e64ab0661645526666c72eb29b44a681c Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 04:03:17 +0800
Subject: [PATCH 69/70] Add some `override`s following commit
 57ab8e6218f5fab869e238037edfc8d6cc94fd59 whose changes were just merged

---
 .../src/mill/main/buildgen/BuildGenBase.scala        |  2 ++
 .../src/mill/main/gradle/GradleBuildGenMain.scala    |  4 +---
 .../src/mill/main/maven/MavenBuildGenMain.scala      | 12 +++++-------
 .../init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala |  4 ++--
 4 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
index 0cfd344c391..f365df07f5a 100644
--- a/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
+++ b/main/init/buildgen/src/mill/main/buildgen/BuildGenBase.scala
@@ -97,5 +97,7 @@ object BuildGenBase {
   trait MavenAndGradle[M, D] extends BuildGenBase[M, D, Tree[Node[M]]] {
     override def getModuleTree(input: Tree[Node[M]]): Tree[Node[M]] = input
     override type OM = M
+
+    override def extraImports: Seq[String] = Seq.empty
   }
 }
diff --git a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
index bc83b1def07..123a2dcaacf 100644
--- a/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
+++ b/main/init/gradle/src/mill/main/gradle/GradleBuildGenMain.scala
@@ -41,7 +41,7 @@ import scala.jdk.CollectionConverters.*
  */
 @mill.api.internal
 object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, JavaModel.Dep] {
-  type C = Config
+  override type C = Config
 
   def main(args: Array[String]): Unit = {
     val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
@@ -185,8 +185,6 @@ object GradleBuildGenMain extends BuildGenBase.MavenAndGradle[ProjectModel, Java
     )
   }
 
-  override def extraImports: Seq[String] = Seq.empty
-
   def getModuleSupertypes(cfg: Config): Seq[String] =
     Seq(cfg.shared.basicConfig.baseModule.getOrElse("MavenModule"))
 
diff --git a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
index e5ceb32c4bf..fcdab872d4c 100644
--- a/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
+++ b/main/init/maven/src/mill/main/maven/MavenBuildGenMain.scala
@@ -37,7 +37,7 @@ import scala.jdk.CollectionConverters.*
  */
 @mill.api.internal
 object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency] {
-  type C = Config
+  override type C = Config
 
   def main(args: Array[String]): Unit = {
     val cfg = ParserForClass[Config].constructOrExit(args.toSeq)
@@ -61,7 +61,7 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
 
   extension (om: Model) override def toOption(): Option[Model] = Some(om)
 
-  def getBaseInfo(
+  override def getBaseInfo(
       input: Tree[Node[Model]],
       cfg: Config,
       baseModule: String,
@@ -126,19 +126,17 @@ object MavenBuildGenMain extends BuildGenBase.MavenAndGradle[Model, Dependency]
     )
   }
 
-  override def extraImports: Seq[String] = Seq.empty
-
   def getModuleSupertypes(cfg: Config): Seq[String] = Seq("PublishModule", "MavenModule")
 
-  def getPackage(model: Model): (String, String, String) = {
+  override def getPackage(model: Model): (String, String, String) = {
     (model.getGroupId, model.getArtifactId, model.getVersion)
   }
 
-  def getArtifactId(model: Model): String = model.getArtifactId
+  override def getArtifactId(model: Model): String = model.getArtifactId
 
   def getMillSourcePath(model: Model): Path = os.Path(model.getProjectDirectory)
 
-  def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] =
+  override def getSupertypes(cfg: Config, baseInfo: IrBaseInfo, build: Node[Model]): Seq[String] =
     Seq("RootModule") ++
       cfg.shared.basicConfig.baseModule.fold(getModuleSupertypes(cfg))(Seq(_))
 
diff --git a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
index ed811d6be62..409b4795410 100644
--- a/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
+++ b/main/init/sbt/src/mill/main/sbt/SbtBuildGenMain.scala
@@ -52,7 +52,7 @@ import scala.collection.immutable.SortedSet
 @mill.api.internal
 object SbtBuildGenMain
     extends BuildGenBase[Project, String, (BuildInfo, Tree[Node[Option[Project]]])] {
-  type C = Config
+  override type C = Config
   override type OM = Option[Project]
 
   def main(args: Array[String]): Unit = {
@@ -198,7 +198,7 @@ object SbtBuildGenMain
 
   private def sbtSupertypes = Seq("SbtModule", "PublishModule") // always publish
 
-  def getBaseInfo(
+  override def getBaseInfo(
       input: (BuildInfo, Tree[Node[Option[Project]]]),
       cfg: Config,
       baseModule: String,

From d0d1e39f836b2199a1034e9a3d1b71786ea71d91 Mon Sep 17 00:00:00 2001
From: Yongshun Shreck Ye <ShreckYe@gmail.com>
Date: Wed, 26 Feb 2025 04:15:10 +0800
Subject: [PATCH 70/70] Update the expected test snapshots and fix the unit
 tests broken by the merge commit 6cac44b60dd2e01e9eb26748018d8a30ce895b5e

---
 .../expected/config/all/sbt-multi-project-example/build.mill     | 1 +
 .../without-base-project/sbt-multi-project-example/build.mill    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
index 82875313c59..b514dff1fbd 100644
--- a/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/all/sbt-multi-project-example/build.mill
@@ -1,5 +1,6 @@
 package build
 
+import _root_.build_.BaseModule
 import mill._
 import mill.javalib._
 import mill.javalib.publish._
diff --git a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
index bdae91e9065..74948bdee64 100644
--- a/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
+++ b/main/init/sbt/test/resources/expected/config/without-base-project/sbt-multi-project-example/build.mill
@@ -1,5 +1,6 @@
 package build
 
+import _root_.build_.BaseModule
 import mill._
 import mill.javalib._
 import mill.javalib.publish._