I think having some diversity in the Rust compiler space is an excellent idea. The rustc monoculture is really bad in the long-term, having multiple compilers a

I think having some diversity in the Rust compiler space is an excellent idea. The rustc monoculture is really bad in the long-term, having multiple compilers allows for creating a much more robust standard (so that implementation bugs doesn't get "baked in" to the language) and benchmarking compile times as well as resulting binaries (in addition to many other benefits). You're right that GCC Rust will probably be behind rustc for a while, but the sooner you start, the sooner it'll get there. The language isn't gonna "settle down" in that way any time soon, might as well just get going as soon as possible.