Maybe a little weird question but do you maybe know a smart watch that can run rust? I got running Egui on my Galaxy Watch 4 with WearOS and I'm thinking if any other watch (other than Galaxy and Pixel) can do that?
Anything that can run C++ should be able to run Rust if you use the LLVM backend, perhaps except when a watch uses musl libc and you rely on some glibc-only call in your program. afaik the only physical devices shipping with musl are car infotainment systems based on l4 kernels and networking hardware (OpenWRT).
no-std Rust has no run-time dependencies of its own.
std Rust runtime-requirements are basically libc, a heap allocator, and a threading library. Many implementations on many OSes are already supported, including musl on Linux. And what's not supported can theoretically be so in the future.
Code generation at build-time is dependent on LLVM, with cranelift and (soon) GCC available as not fully mature alternatives.
3rd party code/crates may impose additional requirements.
Do you mean compiler running on the Watch? Because the compiled code is no longer Rust and therefore there is no reason why it should not run on the Watch. Or do you mean specifically applications with the Rust library Egui?