It cause issue: I had to call cargo update in order to make it use hotglsl v0.2.0 which break the build because ShaderType does not exist since hotglsl switch to use naga instead of glsl-to-spirv.

The project is still using hotglsl v0.1.0 (which does not build on Mac M1) even if its specified in Cargo.toml to use the latest commit in master branch in the repository https://github.com/nannou-org/hotglsl because someone forgot to submit the Cargo.lock updated I guess.
The rule for Cargo.lock is to add it to .gitignore for libraries and include it in history for binaries.

edit: I see in the history 624a596 where it says "including the Cargo.lock in git tracking should not cause any major issues" but still I had to debug that in order to make it build.