Ken Alker writes:
I should have mentioned that I was installing "from source" in the virtual environment (although it still seems to be package management but just Python based instead of OS based as I'm not compiling anything). Would your answer still apply in this situation?
Yes, it does. The list of dependent packages is in mailman/setup.py. Instead of downloading from a distro package repository, the packages are downloaded in the form of "wheels" from pypi.org (the Python Package Index).
In mailmanweb, Postorius, HyperKitty, and django_mailman3 I believe the list is in requirements.txt.
Distros almost never mess with these dependencies, with the single exception of gunicorn for the mailmanweb WSGI server. Distro-defined dependencies are primarily the external webserver (eg. Apache, nginx), the MTA (eg, Postfix, Exim4, Sendmail, qmail), and the relational database management system (eg, PostgreSQL, MySQL).
Alternatives to gunicorn include uwsgi for nginx and Apache, and mod_wsgi for Apache.
Steve