For what it's worth, Python 3.10 will add -fno-semantic-interposition when built with --with-optimizations by default. However, the slow down only affects Pythons built with --enabled-shared anyway.

The issue is discussed here [0]. I also attempted to backport the fix to the official Python Docker image [1], but wasn't able to get much traction. I wish this would land since everyone using these images would get an instant speedup.

[0]: https://bugs.python.org/issue38980 [1]: https://github.com/docker-library/python/issues/501