Several tests in cmdline.pyproject.test result in configuration errors, yet assert == Return code: 0. This is probably bad; they should probably give a return code of 2, for use error. See, for more information, #6003 (because apparently it isn't documented yet). See also #16764, which may be related.

Originally noted by @sterliakov in #19494 (comment), who also had this to say:

I really think this should be fixed, 2 sounds reasonable and consistent with other tools, most Unix tools do that (grep --wtf and ls --not-an-option do exit with 2 on my system, for example, and bad config file is semantically close to bad flags). Note that mypy --wtf also exits with 2, so we have a precedent, and ruff exits with 2 if it finds an unknown key in its pyproject.toml section.