VerifyError with weird circular reference in class def

[som-snytt]

Minimized code

class C:
  object Foo extends Foo.Bar.Base:
    object Bar:
      class Base

@main def test() =
  val c = new C
  val x = new c.Foo.Bar.Base

Output

$ dotc -d /tmp nested.scala && dotr -classpath /tmp test
Exception in thread "main" java.lang.VerifyError: Bad type on operand stack
Exception Details:
  Location:
    C$Foo$.<init>(LC;)V @19: invokevirtual
  Reason:
    Type uninitializedThis (current frame, stack[1]) is not assignable to 'C$Foo$'
  Current Frame:
    bci: @19
    flags: { flagThisUninit }
    locals: { uninitializedThis, 'C' }
    stack: { uninitializedThis, uninitializedThis }
  Bytecode:
    0000000: 2bc7 000b bb00 1959 b700 1cbf 2a2b b500
    0000010: 1e2a 2ab6 0022 b700 25b1
  Stackmap Table:
    same_frame(@12)

        at C.Foo(nested.scala:2)
        at nested$package$.test(nested.scala:8)
        at test.main(nested.scala:6)

Expectation

Anything besides a VerifyError.

[odersky]

This is still an issue in 2021.

[xerial]

I also observed a similar compilation error.

[SethTisue]

note that Scala 2.13.12 rejects object Foo extends Foo.Bar.Base { object Bar { class Base } } with "illegal cyclic reference involving object Foo"