mill.contrib.bloop.Bloop/install run very slow in some case

[harry-xi]

In project ScAllay/ScalaPluginTemplate-WithMill it always take me more then 10 minutes to run it after I change the list of dependencies (whether removing or adding). When using sbt with bloop in a project with similar dependencies, It takes less than a minute to do it. (you can find the project here)

I checked the code for this task and didn't find anything significant. But I still have a suspicion that maybe it re-downloads all the dependencies when there is any change in the dependency list.

[lefou]

Have you tried the Mill built-in BSP server, which is the preferred BSP server and can be installed with mill mill.bsp.BSP/install? See also https://mill-build.org/mill/cli/installation-ide.html#_ide_support

[harry-xi]

I haven't traid it. If you think a try to it can help to find out the problem,l will try it as soon as I have time (maybe a week later).
What more I'm workin on vscode, so bloop seems like my only choice.

[lefou]

You most likely using Metals in vscode, which connects to Mill via BSP the Build Server Protocol. It requires a BSP Server to run. Bloop is on BSP server that is independent of Mill, hence the contrib plugin needs to generate a config for it. Mill BSP is another BSP server, directly supported by Mill. Since not all concepts of Mill can be mapped easily to the Bloop config files, and the bloop contrib plugin haven't seen much contributions (e.g. it is still using a bloop-config-1.5.5), you should definitely give Mill BSP a try. It will also heloful to identify the issues you see. E.g. is Mill BSP also taking that long?

[harry-xi]

You most likely using Metals in vscode, which connects to Mill via BSP the Build Server Protocol. It requires a BSP Server to run. Bloop is on BSP server that is independent of Mill, hence the contrib plugin needs to generate a config for it. Mill BSP is another BSP server, directly supported by Mill. Since not all concepts of Mill can be mapped easily to the Bloop config files, and the bloop contrib plugin haven't seen much contributions (e.g. it is still using a bloop-config-1.5.5), you should definitely give Mill BSP a try. It will also heloful to identify the issues you see. E.g. is Mill BSP also taking that long?

this problem didn't repoduce in mill bsp.

[lefou]

@harry-xi We just merged PR #4600, which looks like it could fix this issue. Maybe you could try that out and report back?

[lihaoyi]

#4600 is only in main, we probably need to backport it to 0.12.x so people can use it in their existing builds