[nine_k]

Both gcc and rustc are good at cross-compiling.

There are many MCUs that run Linux but definitely are incapable of compiling it.

IIRC most of the build time of a rust program is spent not in the rust compilation proper but in LLVM doing code generation and optimization. I hope both LLVM will become more efficient with time, and rust will learn to pass it such IR that it can process faster. There are obvious incentives for both of these things.

But of course it would be sad if the minimum requirements to compile the kernel grew again, and now excluded older RPis.