crash on compilable code:MatchError: Assign(...)

[helloqirun]

scalac compiles but dotc crashes.

$ dotc -version

Dotty compiler version 0.5.0-bin-SNAPSHOT-git-4fefb64 -- Copyright 2002-2017, LAMP/EPFL

$ dotc abc.scala

exception occurred while compiling abc.scala
Exception in thread "main" scala.MatchError: Assign(Apply(Select(This(Ident(JavaInteraction)),protected$count),List(This(Ident(JavaInteraction)))),Apply(Select(This(Ident(JavaInteraction)),protected$count),List(This(Ident(JavaInteraction))))) (of class dotty.tools.dotc.ast.Trees$Assign)
	at dotty.tools.dotc.transform.SuperAccessors.transformAssign(SuperAccessors.scala:395)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:213)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1153)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:63)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:293)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transformStat$2(MacroTransform.scala:45)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transformStats$$anonfun$1(MacroTransform.scala:47)
	at dotty.tools.dotc.core.Decorators$ListDecorator$.loop$1(Decorators.scala:62)
	at dotty.tools.dotc.core.Decorators$ListDecorator$.mapconserve$extension(Decorators.scala:78)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transformStats(MacroTransform.scala:47)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:61)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform$$anonfun$5$$anonfun$1(PostTyper.scala:232)
	at dotty.tools.dotc.transform.SuperAccessors.wrapTemplate(SuperAccessors.scala:410)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform$$anonfun$2(PostTyper.scala:232)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.withNoCheckNews(PostTyper.scala:102)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:233)
	at dotty.tools.dotc.ast.Trees$Instance$TreeMap.transform(Trees.scala:1206)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transform(MacroTransform.scala:55)
	at dotty.tools.dotc.transform.PostTyper$PostTyperTransformer.transform(PostTyper.scala:248)
	at dotty.tools.dotc.transform.MacroTransform$Transformer.transformStat$2(MacroTransform.scala:43)
<snipped>

$ cat abc.scala

package p {
  package a {
    class JavaInteraction(arr: Array[Char])
        extends java.io.CharArrayReader(arr) {
      class Inner {
        {
          count = count
        }
      }
    }
  }
}