buildTarget/changed notification not sent when Scala version changes

[tgodzik]

Version(s)
1.1.0

Describe the bug
Metals depends on notifications from Scala CLI to know when it should request fresh information. When we save and compile file we do get the change notification if we changed for example compiler options but not when the Scala Version changed

To Reproduce

Open a project with:

//> using scala 3.3.1

Run metals doctor and see the correct version being used.

Now changed to:

//> using scala 3.3.0

run doctor again. You will see that the version is still 3.3.1

When checking BSP trace we see that no new notification is sent after the change to new Scala version.

Expected behaviour
Notification is sent to Metals and the version changes.

[Gedochao]

We seem to merely forward this from Bloop.

scala-cli/modules/build/src/main/scala/scala/build/bsp/BuildClientForwardStubs.scala

Lines 13 to 14 in 3dcfb33

	override def onBuildTargetDidChange(params: b.DidChangeBuildTarget): Unit =
	forwardToOpt.foreach(_.onBuildTargetDidChange(params))

We likely should be sending it with our BspClient:

scala-cli/modules/build/src/main/scala/scala/build/bsp/BspClient.scala

Line 20 in 3dcfb33

class BspClient(

A good point to start looking where would be BspImpl

scala-cli/modules/build/src/main/scala/scala/build/bsp/BspImpl.scala

Line 45 in 3dcfb33

final class BspImpl(

The BspClient is initialised in here:

scala-cli/modules/build/src/main/scala/scala/build/bsp/BspImpl.scala

Lines 463 to 465 in 3dcfb33

	actualLocalClient = new BspClient(
	threads.buildThreads.bloop.jsonrpc, // meh
	logger

[tgodzik]

Bloop is unable to see that the project changed because the hash changed, so we need to handle it in Scala CLI

[tgodzik]

Weirdly enough this started to work, only problem is in single file metals scalameta/metals#6755

I am not sure exactly why that is happening or why it fixed.

[Gedochao]

Seems the problem has been fixed, closing this.