Rust bindings to libmupen64plus. Doesn't perform linking as mupen64plus is a shared library.
If you don't have libmupen64plus.(so|dll|dylib) in your system lib dirs, place it at the root of the repo before running cargo test. You can get it for your OS from GitHub releases or build mupen64plus-core from source (make -C mupen64plus-core/projects/unix/Makefile all).