There is a change at https://review.opendev.org/c/zuul/zuul-jobs/+/807702 which is changing the default tox arguments to add "--skip-missing-interpreters false".
This overrides the value from tox.ini file and disallow tox from using another python version than the requested one.
The goal of this change is to prevent accidents where some project endup running tox in CI and believe that these jobs are testing one version of python but in fact another version is used instead.
We think that this has the potential to affect only users of jobs with `parent: tox`. Users that are using `tox-py3*` zuul-jobs are not affected because we force tox to run using that specific python version.
We will wait 2 weeks before merging this change, so people would have time to adapt their configurations.
Potentially affected projects from opendev: https://codesearch.opendev.org/?q=skip_missing_interpreters%20%3D%20%5BtT%5D...
If you find your project on the list above it would be wise to just apply the tox.ini changes mentioned below before we merge that change
If you are affected you have two options: - update your tox.ini file and use generic "py" environment on envlist and remove the skip_missing_interpreters entry. - override tox_extra_args in your tox job in order to keep using the old behavior
Cheers Sorin Sbarnea