Workaround for browser future not being Send

This is incredibly hard to diagnose, because the compiler error is
useless.

lib/tests/integration/browse.rs

@@ -617,20 +617,28 @@ async fn test_recursive_browser() {
         .is_some());
 }
 
+// Test that the future returned by `browser.run...` is `Send`
+fn assert_send<R: Send>(v: R) -> R {
+    v
+}
+
 #[tokio::test]
 // Hit the same node multiple times.
 async fn test_recursive_browser_multi_hit() {
     let (_tester, _nm, session) = setup().await;
 
     let filter = BrowseFilter::new(BrowseDirection::Forward, ReferenceTypeId::References, true);
+
     let to_browse = vec![filter.new_description_from_node(ObjectId::TypesFolder.into())];
-    let res = session
-        .browser()
-        .max_concurrent_requests(3)
-        .handler(filter)
-        .run_into_result(to_browse)
-        .await
-        .unwrap();
+    let res = assert_send(
+        session
+            .browser()
+            .max_concurrent_requests(3)
+            .handler(filter)
+            .run_into_result(to_browse),
+    )
+    .await
+    .unwrap();
 
     assert_eq!(4228, res.nodes.len());
 

opcua-client/src/session/retry.rs

@@ -1,5 +1,6 @@
 use std::time::Duration;
 
+use futures::FutureExt;
 use opcua_types::StatusCode;
 
 use crate::retry::ExponentialBackoff;
@@ -138,7 +139,11 @@ impl Session {
     ) -> Result<T::Out, StatusCode> {
         loop {
             let next_request = request.clone();
-            match next_request.send(&self.channel).await {
+            // Removing `boxed` here causes any futures calling this to be non-send,
+            // due to a compiler bug. Look into removing this in the future.
+            // TODO: Check if tests compile without this in future rustc versions, especially
+            // if https://github.com/rust-lang/rust/issues/100013 is closed.
+            match next_request.send(&self.channel).boxed().await {
                 Ok(r) => break Ok(r),
                 Err(e) => {
                     if let Some(delay) = policy.get_next_delay(e) {