To my knowledge, no, we don't use any python extensions. Unless extensions can be installed via pip, in which case I would need to audit our many dependencies to determine if any of them ultimately pull in any extensions as part of a pip install.

I can't provide a minimal script, no, we don't reproduce it deterministically. Like I said, our application runs all the time and we appear to have about ~200 instances where the problem has been caught by our uncaught exception handling system. The repro of the bug does not appear to have a set correlation with exercise of a particular feature or a particular application state. Given the exception is a thin wrapper around linux syscalls, my guess is something like select(), it's likely the issue has to do with transient network communication problems.