From discussion at dev meeting on 7/12/2023:

Idea is that pandas-stubs project has tests here: https://github.com/pandas-dev/pandas-stubs/tree/main/tests

When changes are merged into main on pandas, the tests in pandas-stubs may reveal bugs or new warnings that current tests in pandas are not picking up. Or the new warnings need to be accounted for in the pandas-stubs tests.

Suggestion is to have some part of the pandas CI do a daily test on the pandas-stubs tests using pytest -Werror and if that test picks up a failure, to auto-create an issue in pandas and/or the pandas-stubs repo so that issue can be investigated and dealt with, either in the pandas code in case of a new exception, or in the pandas-stubs tests if a new warning is being issued.

See pandas-dev/pandas-stubs#742 of an example of a pandas-stubs PR that fixed the tests for pandas-stubs as a result of doing a test on nightly builds of pandas, and #54055, #54056, #54056 and #54059 as a set of pandas issues created as a result of doing the triage that created the pandas-stubs PR.

Tagging a few people who contributed to the discussion: @MarcoGorelli @lthomas1 @mroeschke