Compiler failure in 2.10.x

klist.scala

sealed trait GenericList[+M[_]] {

  final def :^:[A, N[X] >: M[X]](elem: N[A]): GenericCons[N, A, this.type] =
    GenericCons[N, A, this.type](elem, this)

}

case class GenericCons[M[_], H, +T <: GenericList[M]](
  head: M[H],
  tail: T
) extends GenericList[M] {


}

case class GenericNil[M[_]]() extends GenericList[M] {


}

object TypelevelUsage extends App {

  val klist = None :^: Option(3) :^: Some("foo") :^: GenericNil[Nothing]

  // fails
  klist match {
    case GenericCons(optionInt1, GenericCons(optionInt2, GenericCons(someString, _))) =>
  }

  // fails, but with another message
  /*klist match {
    case GenericCons(optionInt1, GenericCons(optionInt2, _)) =>
  }*/

  // succeeds
  klist match {
    case GenericCons(optionInt1, _) =>
  }

}