Weird printing of abstract override

[som-snytt]

reproduction steps

using Scala 2.13.8,

trait A {
  def m(a:Int): Int
}

trait B extends A {
  override def m(a:Int): Int = { return a; }
}

trait C extends A {
  abstract override def m(a:Int):Int = { return super.m(a); }
}

trait D extends B with C {
  override def m(a:Int):Int = { return super.m(a); }
}

trait E extends C with B {
  abstract override def m(a:Int):Int = { return super.m(a); }
}

class X extends E with D

problem

➜  scalac -d /tmp i14415.scala
i14415.scala:22: error: `abstract override` modifiers required to override:
absoverride def m(a: Int): Int (defined in trait C)
  with override def m(a: Int): Int (defined in trait D)
class X extends E with D
      ^
1 error

Or, consider a feature request to support keyword absoverride. Which sounds like the latest workout hack to have a cut bod.

Noticed at scala/scala3#14415