Crashing a Menu Extra

On a current project, whenever a menu extra menu was open and an underlying item was updated, the entire menu extra would crash.  Upon further review here (note “Main Thread Only Classes”), it appears that it is verboten to update the menu item title from a thread other than the main thread.  Check out this git repository for a simple project that used to reproduce the problem and now shows how to set the menu item title properly from a non-main thread.