Greetings. I am attempting a complete Mailman 3 installation on a Debian 10 system that already runs Mailman 2, following this documentation:

https://docs.mailman3.org/en/latest/install/virtualenv.html

Even following this guide, I'd had a lot of issues with permissions, where directories and files were owned by list rather than mailman. After correcting those issues, I then got to the point of checking mailman3's status, and systemctl shows this error:

Nov 19 20:09:57 [REDACTED] mailman[1463]: Error in atexit._run_exitfuncs: Nov 19 20:09:57 [REDACTED] mailman[1463]: Traceback (most recent call last): Nov 19 20:09:57 [REDACTED] mailman[1463]:   File "/usr/lib/python3.7/logging/__init__.py", line 2038, in shutdown Nov 19 20:09:57 [REDACTED] mailman[1463]:     h.flush() Nov 19 20:09:57 [REDACTED] mailman[1463]:   File "/opt/mailman/venv/lib/python3.7/site-packages/mailman/core/logging.py", line 67, in flush Nov 19 20:09:57 [REDACTED] mailman[1463]:     if self._stream: Nov 19 20:09:57 [REDACTED] mailman[1463]: AttributeError: 'ReopenableFileHandler' object has no attribute '_stream'

There is an October 2019 thread on this error [1] but I think it's in a different context, where the OP already had mailman3 running, and was trying to migrate Mailman 2 lists.

Also, regarding those permissions issues above, it matters which "layout" value is in /etc/mailman3/mailman.cfg. I'd tried "dev" because I saw a post from Mark Sapiro recommending that, but then mailman3 wanted me to create a bunch of directories under /etc, even though $var_dir was set to /var/lib/mailman3. Things seem to go better, except for the confusion between lists/mailman ownership, when I set layout to "debian", which was the default.

Thanks in advance for clues on addressing the ReopenableFileHandler error above.

dn

[1] https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/thread/7...