So, after BALUG (VM balug) upgraded from Debian 12 to 13 starting after 2026-01-28T03:50:34Z, significant issues, most notably at least mailman3 web related stuff wasn't working. This was mostly resolved by 2026-02-09T20:53:03Z

And ... lots of details. Since this month's BALUG meeting has discussion topic of Testing & Troubleshooting, posted much of the relevant to the BALUG-Talk list, and archive of that posting is available here: https://lists.balug.org/mailman3/hyperkitty/list/balug-talk@lists.balug.org/...