> Without a specification how do we know which Rust implementation is correct and which has bugs?
The gcc-rs project answers this question explicitly in their FAQ, which I've linked downthread:
> If gccrs interprets a program differently from rustc, this is considered a bug.
They also go on to say:
> Once Rust-GCC can compile and verify all Rust programs, this can also help figure out any inconsistencies in the specification of features in the language. This should help to get features right in both compilers before they are stabilized.
If you're looking for a specification, additional implementations help that effort, not hurt it.
The gcc-rs project answers this question explicitly in their FAQ, which I've linked downthread:
> If gccrs interprets a program differently from rustc, this is considered a bug.
They also go on to say:
> Once Rust-GCC can compile and verify all Rust programs, this can also help figure out any inconsistencies in the specification of features in the language. This should help to get features right in both compilers before they are stabilized.
If you're looking for a specification, additional implementations help that effort, not hurt it.