Compiler crash: is not a simple name while compiling

[biboudis]

class Test[T1] {
  class A[T2]

  object B  {
     def m(): A[B.type] = ???
  }
}

java.lang.UnsupportedOperationException: B[ModuleClass] is not a simple name while compiling tests/pos/ranks.scala
Exception in thread "main" java.lang.UnsupportedOperationException: B[ModuleClass] is not a simple name
        at dotty.tools.dotc.core.Names$DerivedName.asSimpleName(Names.scala:474)
        at dotty.tools.dotc.core.Names$DerivedName.asSimpleName(Names.scala:474)
        at dotty.tools.dotc.core.Names$TypeName.asSimpleName(Names.scala:441)
        at dotty.tools.dotc.transform.GenericSignatures$.classSig$2(GenericSignatures.scala:167)
        at dotty.tools.dotc.transform.GenericSignatures$.jsig$1(GenericSignatures.scala:228)
        at dotty.tools.dotc.transform.GenericSignatures$.boxedSig$1(GenericSignatures.scala:64)
        at dotty.tools.dotc.transform.GenericSignatures$.argSig$1(GenericSignatures.scala:145)
        at dotty.tools.dotc.transform.GenericSignatures$.classSig$1$$anonfun$1(GenericSignatures.scala:174)

scalac passes

[ashwinbhaskar]

Can I give the fix a shot?

[biboudis]

Yes, much appreciated! Try tracking the error using the guide can help

https://dotty.epfl.ch/docs/contributing/debugging.html

Either send a PR with the fix, ask questions on gitter or pot your progress here when you reach a point that you couldn't progress further 🎉

[ashwinbhaskar]

thank you:) Can you assign the issue to me?

[biboudis]

Feel free to work on it but if you feel that you don't want work on it anymore or it takes a long time (let's say more than a week without progress), don't fear the "Unassign me" button. This mark this up for grabs for others as well! First step, try if its still reproducible on master.

[ashwinbhaskar]

@biboudis okay:) Yes it is reproducible on master