Thinking about the dangers of subtle incompatibilities, I think the existence of crater[1] could make a huge difference, once alternative implementations are fa

Thinking about the dangers of subtle incompatibilities, I think the existence of crater[1] could make a huge difference, once alternative implementations are far enough along. Arguably the nearest thing to a specification for the Rust language at present is "what crater would be happy with". That seems more useful than thinking of rustc as a reference implementation, because when I read the release notes every now and again they say things to the effect of "this change is technically backwards-incompatible but crater reassures us that it won't cause anyone any trouble". [1] https://github.com/rust-lang/crater https://github.com/rust-lang/crater