GeezerVison

LGTM

Great work! 👍

I'm confused by "compatibility mode" wording whereas the env var is called "perf support". I would prefer to say that -X perf enables support for the Linux perf tool.

"Enable" support or "Add" support, not sure which one makes more send. Technically, the option adds something ;-)

The PyConfig member, the env var and the -X option have 3 different names which also confuse me. Would it make sense to rename the -X option to -X perfsupport to make it more consistent? If yes, I would suggest doing that in a separated PR.

The name "perf" is very generic and can mean many things. A newcomer might read it as: "use -X perf to get best performance" :-)

For me, "compatibility mode" sounds like "backward compatibility mode".

thanks for the edits!

Ezio made many interesting comments. I will wait until they are addressed to review again the PR ;-)

Thanks a lot for the fixes! ❤️

I plan to land this this week as all the feedback has been addressed but I will give some time in case someone wants to request some further changes.