[Mailman-Developers] Development setup confusion

I think a setup step might be missing from the developer's docs https://docs.mailman3.org/en/latest/devsetup.html

If I go through the venv setup and when I call mailman info, the following error shows up (missing dependency).

... File "/home/_/Workspace/personal/mailman/src/mailman/__init__.py", line 38, in <module> from mailman.core.i18n import initialize File "/home/_/Workspace/personal/mailman/src/mailman/core/i18n.py", line 22, in <module> from flufl.i18n import PackageStrategy, registry ModuleNotFoundError: No module named 'flufl.i18n'

However, when I run just run tox, the .tox/qa/bin/mailman info command works without any issues.