scala/collection/TraversableOnce.scala issues

[DarkDimius]

dotc ./scala-scala/src/library/scala/collection/TraversableOnce.scala
./scala-scala/src/library/scala/collection/TraversableOnce.scala:437: error: class OnceCanBuildFrom needs to be abstract, since def apply:
  (from: [+hk$0] => scala.collection.TraversableOnce[hk$0])
    scala.collection.mutable.Builder[
      scala$collection$TraversableOnce$OnceCanBuildFrom$$A
    ,
      scala.collection.TraversableOnce[
        scala$collection$TraversableOnce$OnceCanBuildFrom$$A
      ]
    ] is not defined
(Note that TypeRef(ThisType(TypeRef(ThisType(TypeRef(NoPrefix,generic)),CanBuildFrom)),scala$collection$generic$CanBuildFrom$$From) does not match RefinedType(TypeRef(ThisType(TypeRef(NoPrefix,collection)),TraversableOnce), scala$collection$TraversableOnce$$A, TypeBounds(TypeRef(ThisType(TypeRef(NoPrefix,scala)),Nothing), TypeRef(ThisType(TypeRef(NoPrefix,scala)),Any)) | 1651380528))
  class OnceCanBuildFrom[A] extends BufferedCanBuildFrom[A, TraversableOnce] {
          ^
one error found