Repeating this comment here in the hopes it gets greater visibility. The MacPython/matplot-lib repo builds and uploads wheels weekly, and also can provide them for uploading to PyPI. It has been broken for a while. I tried reviving it in a PR to move the x86 builds to github actions, and leave only the arm64 ones on travis.com.

Should the arm64 and i686 ones be failing? The strategy in that repo is to build in a docker image and to test in a different one, perhaps that is breaking the image tests?