We don't need to bootstrap from scratch, Rust (via LLVM) can cross-compile very easily once riscv64 support is added.
In practise I am already cross-compiling amd64->mips/mipsel for every stable Rust release on my home box, because a native mips rustc compile runs out of memory on those 32-bit machines. [1] The cross-compiled mips works completely fine to build smaller rust packages, e.g cargo [2] ripgrep [3]
Yeah back with 1.14 or so I set up some cross (and native) toolchains for mipsel with the intent of putting some stuff on my ER-X. While it was a giant pain in the dick with the unsupported version of Debian Ubiquiti was using, it was doable. Cross compiling on Debian has come a long way (altho I'm using crosstool-ng on OSX these days which is fairly slick).
We don't need to bootstrap from scratch, Rust (via LLVM) can cross-compile very easily once riscv64 support is added.
In practise I am already cross-compiling amd64->mips/mipsel for every stable Rust release on my home box, because a native mips rustc compile runs out of memory on those 32-bit machines. [1] The cross-compiled mips works completely fine to build smaller rust packages, e.g cargo [2] ripgrep [3]
[1] https://github.com/rust-lang/rust/issues/56888 [2] https://buildd.debian.org/status/package.php?p=cargo [3] https://buildd.debian.org/status/package.php?p=rust-ripgrep