[grey-area]

The problems with homebrew packages at present are mostly down to projects like Go and Rust not being updated for M1 ARM yet and hence sources not compiling properly rather than a problem with homebrew itself. So users attempting to compile from original upstream sources would run into similar problems.

They have an overview issue here:

https://github.com/Homebrew/brew/issues/7857

[steveklabnik]

Rust does have tier 2 support, but it hasn’t made its way to stable yet. This means if you did try in upstream today, it would work.