If I reproduce the steps from the HACKING.md and TESTING.md I can no longer run the static and unit tests. The steps from HACKING.md to setup the test containers are: - ./tools/environment-setup.sh - lxc exec snapcraft-dev -- sudo -iu ubuntu bash This works ok. Then the instructions in TESTING.md: - make tests-static - make test-units They both give: (snapcraft) ubuntu@snapcraft-dev:~/snapcraft$ make tests-static tox run -e lint-black ROOT: will run in automatically provisioned tox, host /home/ubuntu/.venv/snapcraft/bin/python3 is missing [requires (has)]: tox==4.4.6 (4.0.11), tox-ignore-env-name-mismatch==0.2.0.post2 Traceback (most recent call last): File "/home/ubuntu/.venv/snapcraft/bin/tox", line 8, in <module> sys.exit(run()) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/run.py", line 19, in run result = main(sys.argv[1:] if args is None else args) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/run.py", line 41, in main result = provision(state) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/provision.py", line 124, in provision return run_provision(provision_tox_env, state) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/provision.py", line 142, in run_provision tox_env: PythonRun = cast(PythonRun, state.envs[name]) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/session/env_select.py", line 317, in __getitem__ return self._defined_envs[item].env File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/session/env_select.py", line 181, in _defined_envs run_env = self._build_run_env(name) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/session/env_select.py", line 242, in _build_run_env runner = REGISTER.runner(cast(str, env_conf["runner"])) File "/home/ubuntu/.venv/snapcraft/lib/python3.8/site-packages/tox/tox_env/register.py", line 72, in runner return self._run_envs[name] KeyError: 'ignore_env_name_mismatch' make: *** [Makefile:14: test-black] Error 1