[phicoh]

I think there are a lot of people who don't want a new compiler every few months. Obviously, the people who arrive first at a new language are people like the latest greatest.

Take for example reproducible builds. Obviously, you only get the same binary output if you use the same compiler version. In that context, it doesn't make sense to keep around every version ever released of the Rust compiler.

In particular, if operating systems are going to use Rust in their kernels or base systems, then it is very unlikely that they are just going to use rustup to get the latest compiler. They will carefully vet each compiler release to make sure that everything that worked in the past, still works.

Rust being a compiler means that for every processor architecture somebody has to create the back-end. This means that if the current LLVM-based rust compiler will remain the only usable Rust compiler, there will be a lot of places where Rust cannot be used (unless LLVM will be the only compiler back-end in the future).

[tialaramex]

For now, at least, Rust for Linux actually requires Nightly features, so it's even less stable than the requirements of many relatively fast moving but popular Rust crates in userspace.

As with Firefox, Linux (ab)uses the compiler's own environment hack to say "No, I want nightly features, I don't care that this invalidates my warranty" despite using a stable compiler.

The actual version used is, I think, currently 1.66 (so, about three months old).