Why implicitly[sourcecode.Enclosing] inside T.source fails to compile?

[jk-1]

I have following build.sc module

object myScalaMod extends ScalaModule {

  override def scalaVersion: Target[String] = "2.13.6"

  override def ammoniteVersion: Target[String] = "2.4.0"

  def fooSources: Source = T.source {
    val enclosing = implicitly[sourcecode.Enclosing]
    println(s"enclosing: ${enclosing}")
    os.pwd / 'src
  }
}

When trying to run it:

mill show myScalaMod.fooSources
Compiling /home/jk/workspace.exp/hands-on-scala/mill01/build.sc
Error while emitting build.sc
value enclosing
Compilation Failed

If I comment out the line println(s"enclosing: ${enclosing}") the file compiles fine.

This error happens only with T.source, not with T, T.task, T.input, T.worker, T.persistent or plain old scala function.

Is this bug or why is T.source behaving differently from others?

Is it possible to get more detailed error message on this? At least line number would be very valuable information.

[lefou]

Thanks for reporting this issue. I think this is an oversight in the implementation. I'm creating an issue from this discussion.

[lefou]

I create issue #1541.

[lefou]

#1541 was merged and the issue should be fixed.