Depends on how "crashing" works on OSX. Usually the "Plugin takes to long to whatever" message is displayed when run inside an event listener. If you have a command it's probably different.
If you think that the call takes to long, either run it asynchronously with `subprocess.Popen()` and check periodically with `sublime.set_timeout()` or run it in a new thread using thread or threading module.
You could also try `sublime_plugin.run_timed_function(callback, "plugin name", "event/function name", timeout_in_floating_seconds)` and see if it shows the msg.