Crasher about miniboxing-plugin HOT 1 CLOSED

package miniboxing.tests.compile
import miniboxing.plugin.minispec

abstract class Dist[@minispec A] {
  def apply(a: A): A

  def iterateUntil() = new Dist[A] {
    def apply(a: A): A = ???
  }
}

exception when typing final class $anon extends Object with miniboxing.tests.compile.Dist_L {
  def <init>($outer: miniboxing.tests.compile.Dist_J): anonymous class $anon = {
    $anon.super.<init>();
    ()
  };
  def apply(a: Object): Object = scala.this.Predef.???();
  <synthetic> <paramaccessor> private[this] val $outer: miniboxing.tests.compile.Dist_J = _;
  <synthetic> <stable> def miniboxing$tests$compile$Dist_J$$anon$$$outer(): miniboxing.tests.compile.Dist_J = $anon.this.$outer
}/class scala.reflect.internal.Trees$ClassDef
class Dist_L needs to be a trait to be mixed in in file gh-bug-18.scala
scala.reflect.internal.Types$TypeError: class Dist_L needs to be a trait to be mixed in