Function debug_dump_dir 

pub fn debug_dump_dir() -> PathBuf

Directory the shader debug dumps are written to.

This is std::env::temp_dir: $TMPDIR where set, a per-user directory on macOS, %TEMP% on Windows. Deliberately not a hardcoded /tmp — that is not even an absolute path on Windows, and a predictable name in a world-writable directory is a symlink hazard on multi-user systems, which is why the transpiler dump is written 0600.