Bug report

Bug summary

The MacOSX matplot backend fails with animation in certain Python scripts. On other platforms (Windows and Linux) the same animation from the same script works fine with their default backends: https://retifrav.github.io/blog/2020/09/05/matplotlib-animation-macos/video/animation.mp4

The animation also works fine on Mac OS with TkAgg backend.

Code for reproduction

The full script is a bit long, so I published it here: https://gist.github.com/retifrav/b884ce647c8ef26678c2b6408d4b8306

Actual outcome

No animation being played, not even the first frame.

Expected outcome

The animation plays like it does on Windows and Linux platforms (as it's shown on the video in the beginning of this report).

Matplotlib version

• Operating system: Mac OS 10.15.6
• Matplotlib version: 3.3.1
• Matplotlib backend: MacOSX
• Python version: 3.8.5
• Other libraries: numpy 1.19.1

Python was installed using Homebrew, matplotlib was installed using pip.

Original thread at the forum.