A strange "Exception: Xlib's XInput extension is required, but could not be found." error

[user202729]

Just now I got that error. Thankfully I got it resolved quickly (otherwise I would be fixing it rather than writing this long post with Plover)

Not sure what was going on exactly, but previously I had python-xlib 0.29 and python3-xlib 0.15 which causes the error. And python3-xlib is unmaintained. https://stackoverflow.com/questions/74716030/what-is-the-difference-between-python-xlib-python3-xlib-pyxlib-and-xlib-in-pyt

python3-xlib was probably pulled in by pyautogui. (now I try to reinstall those packages but cannot reproduce the issue.)

Anyway, just put here for documentation purpose. If something goes wrong try to reinstall packages first (or make a new virtual environment)