java.lang.InternalError: Malformed class name on jmh:run about sbt-jmh

[jrudnick]

Perhaps this is the root cause? https://issues.scala-lang.org/browse/SI-2034

[atk91]

Is this ever going to be fixed?

[jrudnick]

After trying to reproduce with similar code above, in an isolated environment was not able to reproduce. I will try to get a small, accurate reproducer and attach it to this issue or I will close the issue.

[jrudnick]

@Updated the description with more specific steps towards basic reproduction. Fundamentally, this may be an issue between JMH and Scala, and not directly related to sbt-jmh. It appears, that calling getCanonicalName on doubly nested (in objects) traits isn't something that Scala likes. As it stands now the error that you see when you try to run is highly cryptic. Perhaps, there is something that sbt-jmh can provide to make it less so?

[ktoso]

It appears, that calling getCanonicalName on doubly nested (in objects) traits isn't something that Scala likes.

Yeah that's exactly the thing I was thinking about.
I think the fact of nesting inside classes already causes tricky name problems.
I'm not sure sbt-jmh is able to do anything about it, since it does not even own the thread (nor even jvm!) that this error will come up on...

I can't come up with a way to help out from my end on this one... would you mind if we close as scala issue?

[jrudnick]

I guess there is no way in JmhPlugin.scala to at least report the file that is providing the issue?

[ktoso]

I don't really see how we could, if people google for it they'll find this issue.
I'll close for now. Thanks for the research though!

[jvican]

Also having the same problem. Unfortunately, the codebase I tried this on is huge and I cannot spend too much time on this. Sad to see that SI-2034 is still not solved.

[joshlemer]

@jrudnick while the exception does not inform you which class throws the exception, you can attach a debugger to an SBT task (for example in IntelliJ) and set a breakpoint at java/lang/Class.java line 1330 to inspect the name of the class that is allegedly malformed.

[Reeebuuk]

In my case it was an enumeratum object.

  sealed trait Status extends EnumEntry

  object Status extends Enum[Status] {

    val values: scala.collection.immutable.IndexedSeq[Status] = findValues

    case object Draft extends Status
    ...
  }

java.lang.Class:1330

simpleName had value Draft$ which breaks the simpleName.charAt(0) != '$' condition.