Upgrade xcode cli tools to the most recent (this takes a while):
$ softwareupdate --list
$ softwareupdate --install "Command Line Tools for Xcode-13.4"
Watch pyenv not be able to install anything (pyenv/issues/2143), because of what seems to be a mismatch across Python, Clang and Monterey (issue45405).
Update pyenv to pick up patched versions that work (3.10.3+, 3.9.13, 3.9.9, 3.8.13, 3.7.13).