It works OK as long as you are running Python from a framework build (--enable-framework). There are various OS X customizations in IDLE that are currently triggered by the runningAsOSXApp() function in idlelib/macosxSupport.py. One of the customizations is to add the event binding for <Control-Button-1> (in idle lib/EditorWindow.py). Restricting the customizations to framework builds is not useful nor correct and there are some other questionable customizations assumptions made in that module. I'll work up a patch. In the meantime, you can easily workaround it for testing by patching runningAsOSXApp to always return True.