A word of warning on this. It uses a custom fork of LLVM/Clang/Rust which adds support for a new architecture. The tooling that sets up this environment has failed in obscure ways each time I’ve attempted to set up and build one of their own hello world samples.

The llvm patches were up streamed a few weeks ago, so that should help significantly once it trickles into releases of the actual compilers.

Have you tried with espup(https://github.com/esp-rs/espup)? We`ve updated Xtensa tooling not long ago, for more details have a look at the book: https://esp-rs.github.io/book/installation/installation.html...

Support for the ESP8266 I had sitting in my desk drawer is a little rough, the code templates they provide don't seem to work out of the box. I gave up and am just buying an ESP32. Should be a much better experience, I'm hoping.