@early-needle-54791: re: traps crossing the cffi boundary. function pointers need to have the appropriate shape: https://github.com/pantsbuild/pants/blob/55a562c772aea7693f0ae805487ad4e7998056c4/src/rust/engine/src/externs.rs#L23-L25 vs https://github.com/pantsbuild/pants/blob/55a562c772aea7693f0ae805487ad4e7998056c4/src/python/pants/engine/native.py#L285-L291 , for example