Sorry if I'm not supposed to open closed issues, however I believe there's a typo in the whatsnew page for this. In https://docs.python.org/3.10/whatsnew/changelog.html#changelog, the entry for bpo-43963 says "Importing the signal module in a subinterpreter has no longer side effects.", however I believe it should be "Importing the signal module in a subinterpreter no longer has side effects". The only difference is that "has" is moved after "no longer" instead of before.