Scott Talbert

The provided info helps, thanks. It seems there are probably several issues here - the crash seems to be a GIL management issue, probably the same crash as reported in...

Are you possibly mixing GTK2 and GTK3 (wxPython) in your app somehow? https://stackoverflow.com/questions/61509812/issue-glib-gobject-warning-cannot-register-existing-type-gdkdisplaymanager

> If this is the issue, then I suppose I'll need to find a version wxPython that can be built with gtk2. Does that sound right? Not necessarily. My question...

matplotlib is a good suspect. If it's trying to use GTK-2, that could be a problem.

Fixed by #2573.

@reticulatus did this work in previous Python or wxPython versions on macOS?