Before you intend to release a new version of neutron-lib consider posting a sentinel patch that will allow to validate that the neutron-lib hash chosen for tagging is not breaking gate or check jobs affecting a project you care about, first and foremost Neutron.
As the patch shows, upper-constraints must be bypassed and that may itself lead to failures due to upstream package changes. The patch also shows (expected) Grenade failures in that Grenade pulls its own upper-constraints file during the upgrade phase. In general a newer version of neutron-lib is validated through the Tempest -full job (and Grenade runs a subset of it), so Grenade failures can be safely ignored.
In any other case consider (for failures caused by unpinned global requirements) hard-coding a dummy upper-constraints file that itself uses the specific neutron-lib hash you want to test. Furthermore, consider using a commit header that starts with DNM (Do Not Merge) to indicate that the change is just a test, or -2, if you have the right access permissions.
It is also worth noting that every Stadium project will have a periodic job running unit tests and pep8 against the master version of neutron-lib Checking Grafana’s periodic dashboard can give you a glimpse into the sanity of the integration between neutron-lib and the Stadium projects, and can be considered the quick check before going ahead with a full blown sentinel patch. Periodic failures can be debugged by viewing the periodic logs
In addition, both the API reference as well as the project docs should be
validated to ensure there are no dead links. To do so run
tox -e linkcheck and address the errors.