@IntrusionCM I definitely agree it sucks. But it's so unfortunate that we have to understand both 2.12 and 2.13 collection architectures in at least 1 year in the future because Spark etc. is not going to keep up that soon.

@yellow-dog It is a breaking change because a lot of `*Like` traits are gone, `Traversable` trait is gone, CanBuildFrom is gone, etc.

Sure, for common collection types (List, Map, etc.) most things ain't breaking. but I'd definitely classify the API change in general as breaking. Otherwise, there's no need for an official migration guide. https://docs.scala-lang.org/overvie...