crash with "java.lang.IllegalArgumentException: requirement failed"

[helloqirun]

$ cat abc.scala

class ann {
  @ann({ def baz })
  def foo()
}

$ dotc abc.scala

-- [E018] Syntax Error: abc.scala --------------------------------------------------------------------------------------
3 |  @ann({ def baz })
  |                ^
  |                missing return type

longer explanation available when compiling with `-explain`
-- [E018] Syntax Error: abc.scala --------------------------------------------------------------------------------------
4 |  def foo()
  |           ^
  |           missing return type

longer explanation available when compiling with `-explain`

exception occurred while typechecking abc.scala

exception occurred while compiling abc.scala
Exception in thread "main" java.lang.IllegalArgumentException: requirement failed
	at scala.Predef$.require(Predef.scala:207)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation.enterNoReplace(SymDenotations.scala:1548)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation.enter(SymDenotations.scala:1538)
	at dotty.tools.dotc.typer.NamerContextOps$class.enter(Namer.scala:34)
	at dotty.tools.dotc.core.Contexts$Context.enter(Contexts.scala:57)
	at dotty.tools.dotc.typer.Namer.enterSymbol(Namer.scala:334)
	at dotty.tools.dotc.typer.Namer.dotty$tools$dotc$typer$Namer$$recur$1(Namer.scala:417)
	at dotty.tools.dotc.typer.Namer.indexExpanded(Namer.scala:427)
<snipped>

[liufengyun]

Report confirmed, thanks @helloqirun !

[odersky]

This has to do with the fact that the annotation argument is typed with the enclosing class as owner, whereas the owner should be the localDummy of the template. Does not look so easy to fix though.