Looks like you've found an X11 bug.
I don't where the X11 bug tracker is. Somewhere in https://gitlab.freedesktop.org/ probably.

I'd exclude the failing tests for now and add a note somewhere to revisit the exclusions in a month or two.

Rather than putting -x test_ctypes test_crypt test_decimal test_faulthandler test_interpreters test___all__ test_idle test_tix test_tk test_ttk_guionly test_ttk_textonly list in the CI configuration, what do you think of adding an option to regrtest, similar to --pgo? Example: add --asan option.

Rather than putting -x test_ctypes test_crypt test_decimal test_faulthandler test_interpreters test___all__ test_idle test_tix test_tk test_ttk_guionly test_ttk_textonly list in the CI configuration, what do you think of adding an option to regrtest, similar to --pgo? Example: add --asan option.

👍 Makes sense, that's clearly a better option

--pgo describes what it does, whereas --asan would not.
I know it is clumsy to have to list all the exceptions, but that makes it clear what is excluded.
We want to make the list shorter, having this long list makes it clear what needs fixing.

Yeah, that makes sense, although it may be worth to also add some option so you can easily run this locally. I think we should also add something to the devguide about what is excluded and why.

In any case, I am going to merge this and add the option to regrtest in a separate PR.

I know it is clumsy to have to list all the exceptions, but that makes it clear what is excluded.

My concern is that there is also an ASAN buildbot, and this denylist is copied manually. It increases the maintenance burden. Well, since @pablogsal runs the buildbot, he is likely eagger to maintain these two lists manually ;-)

Maybe an option is not needed, and regrtest could detected if Python was built with ASAN using sysconfig to get compiler flags.

We want to make the list shorter, having this long list makes it clear what needs fixing.

Sure, it would be great to skip less tests ;-)