One of the formula not working in Homebrew’s core functionality is the gcc compiler, which they expect might be ready by mid-2021. Another is Go, which iirc they’re expecting will begin working around January. Rust and Erlang aren’t ready, MySQL doesn’t even get past the build phase, and Python is only partially working.
You can track progress here. Be advised that packages listed as ‘check again when XYZ is fixed’ may themselves have issues that can’t yet be discovered.
