Related threads:
- Use lld by default on Windows to mitigate Microsoft C++ Build Tools licencing issues
- Pre-RFC: Remove Rust's dependency on Visual Studio in 4 (...complex?) steps
- Visual Studio Build Tools licensing
Summary: LLVM's MSVC abi has a hard coded dependency on MSVC C++ exception handling (for panics). We would either need to reverse engineer that (which is difficult) or else wait for the vcruntime to be open sourced (which might be awhile).