Are there any known examples of minor, uncontroversial language “warts” that would go in such a repo?
All the minor language changes I’m personally aware of are either highly controversial (or at least, high relative to the small potential benefits, like the : vs = in structs thing or this *const T thing) or don’t even need editions and can just go through an ordinary warning cycle and then get deprecated. https://github.com/rust-lang/rust/issues/30459 being a good example. We could use an edition to just wipe out all deprecated items, but since the compiler has to continue supporting all those items for older editions anyway, I assume there’s no point in doing that.