Huh? Linux on arm, i686, mips, ppc all have rustup installers. I'm not sure if that formally makes them "Tier 1" platforms but it does mean that they're pretty darn well supported by rust. Are the Alpine folks having problems because they're not using GNU libc?
IIRC, at some point rustc was not able to self-host on 32 bit platforms due to the amount of virtual memory it used. I don't know if it has been fixed yet, but I can imagine that this would be an issue if you want your entire package repository to be self-hosting.
The challenge might be bootstrapping. rustc makes a habit of capitalizing on just-introduced features, and they only require that you have the prior release. So to build rustc 1.x, you have to build 1.(x-1) first.
Also -- packaging. rustup might be available but the distros generally prefer their own native packaging system.
When bootstrapping a new arch, you usually cross-compile to get it working. This means that you don't need to build all of those builds. If you want to start a new bootstrap chain, which is what most distros have done, you do this once and then go from there as new releases come out.
Yeah I'm somewhat familiar with getting rust bootstrapped, I still have the 15/16/17 rust toolchains built for mipsel kicking around. Worst part of that was targeting wheezy though.
It just seems odd that these architectures seem to have official rust support but are being problematic on Alpine. Self-hosting might be a sticking point, but seems a bit of a silly one given how slow some of those architectures are.
> Firefox is only available on x86_64 due to Rust.
Could someone explain the reasoning behind this? I’m not familiar with whatever restrictions Rust may impose.