In this PR about PEP-6222 I created an experimental build of Python 3.10 that is available at this binder link. However if I install IPython using py10 -m pip install IPython and then try to use it, eventually I get a crash. I'll post the details in a comment below so we keep the top-level issue description simple. It would be great to track 3.10 compatibility, if possible, so we can use IPython for testing/experimenting with new features and ideas (though I realize that may be a big lift in that it's tracking quite a moving target).