Comment 16 for bug 1906322

Looks like this bug has cropped up on stable/wallaby today, seeing this error on failing grenade jobs [1][2]:

022-06-01 18:33:39.549 | full installdeps: -c/opt/stack/new/requirements/upper-constraints.txt, -r/opt/stack/new/tempest/requirements.txt
2022-06-01 18:33:41.439 | ERROR: invocation failed (exit code 1), logfile: /opt/stack/new/tempest/.tox/tempest/log/full-1.log
2022-06-01 18:33:41.439 | ================================== log start ===================================
2022-06-01 18:33:41.439 | Looking in indexes: https://mirror.mtl01.iweb.opendev.org/pypi/simple, https://mirror.mtl01.iweb.opendev.org/wheel/ubuntu-20.04-x86_64
2022-06-01 18:33:41.439 | DEPRECATION: Constraints are only allowed to take the form of a package name and a version specifier. Other forms were originally permitted as an accident of the implementation, but were undocumented. The new implementation of the resolver no longer supports these forms. A possible replacement is replacing the constraint with a requirement.. You can find discussion regarding this at https://github.com/pypa/pip/issues/8210.
2022-06-01 18:33:41.439 | ERROR: Links are not allowed as constraints
2022-06-01 18:33:41.439 | WARNING: You are using pip version 21.0.1; however, version 22.1.2 is available.
2022-06-01 18:33:41.439 | You should consider upgrading via the '/opt/stack/new/tempest/.tox/tempest/bin/python -m pip install --upgrade pip' command.
2022-06-01 18:33:41.439 |
2022-06-01 18:33:41.439 | =================================== log end ====================================
2022-06-01 18:33:41.440 | ERROR: could not install deps [-c/opt/stack/new/requirements/upper-constraints.txt, -r/opt/stack/new/tempest/requirements.txt]; v = InvocationError('/opt/stack/new/tempest/.tox/tempest/bin/pip install -c/opt/stack/new/requirements/upper-constraints.txt -r/opt/stack/new/tempest/requirements.txt', 1)
2022-06-01 18:33:41.440 | ___________________________________ summary ____________________________________
2022-06-01 18:33:41.440 | ERROR: full: could not install deps [-c/opt/stack/new/requirements/upper-constraints.txt, -r/opt/stack/new/tempest/requirements.txt]; v = InvocationError('/opt/stack/new/tempest/.tox/tempest/bin/pip install -c/opt/stack/new/requirements/upper-constraints.txt -r/opt/stack/new/tempest/requirements.txt', 1)
2022-06-01 18:33:41.475 | + lib/tempest:install_tempest:1 : exit_trap

[1] https://zuul.opendev.org/t/openstack/build/09f7ff5b69b84e429e3141a622dfa951/log/controller/logs/grenade.sh_log.txt#16798
[2] https://zuul.opendev.org/t/openstack/build/0f98cf442e56467db4f67a5b3c6a6138/log/controller/logs/grenade.sh_log.txt#16769