Thanks Samuel. You're advise was a great help. Event though the module is called  "macfsevents" and can be installed with `pip install macfsevents`, it should be imported as `import fsevents`... I've replaced `depends_on 'macfsevents' => :python` with `depends_on 'fsevents' => :python` and this solved the issue. I'll update my pull request in a minute.