018-10-23 13:54:08.643 python[48930:2909663] *** Assertion failure in +[NSUndoManager _endTopLevelGroupings], /BuildRoot/Library/Caches/com.apple.xbs/Sources ...

Just to share the problem I meet and how I resolve it. 20.2.3 (this is the latest version of pip in 2020-09-23 15:52:46 Beijing Time). However my opencv-python was installed when I was with an old ...