Hi all,
after upgrade from Ubuntu 25.10 (python3.13) to 26.04(python3.14) and
root@bywater ~ # python3 -m venv /opt/mailman/venv/
minutely: Traceback (most recent call last): File "/opt/mailman/venv/bin/mailman-web", line 3, in <module> from mailman_web.manage import main ModuleNotFoundError: No module named 'mailman_web'
root@bywater /opt/mailman/venv/bin # ll mailm* -rwxr-xr-x 1 mailman www-data 204 Nov 5 2025 mailman* -rwxr-xr-x 1 mailman www-data 203 Nov 5 2025 mailman-web*
root@bywater ~ # lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 26.04 LTS Release: 26.04 Codename: resolute
root@bywater ~ # dpkg -l python3 ┌── Desired=Unknown/Install/Remove/Purge/Hold │┌─ Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend ││┌ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) │││ Name Version Architecture Description ├┼┼─══════════════─═══════════════─════════════─═══════════════════════════════════════════════════════════════════════> ii python3 3.14.3-0ubuntu2 amd64 interactive high-level object-oriented language (default python3 versio>
root@bywater /opt/mailman/venv/lib/python3.14/site-packages # ll total 16 drwxr-x--- 4 root root 4096 Aug 13 15:09 ./ drwxr-x--- 3 root root 4096 Aug 13 15:09 ../ drwxr-x--- 5 root root 4096 Aug 13 15:09 pip/ drwxr-x--- 3 root root 4096 Aug 13 15:09 pip-25.1.1.dist-info/
In an older thread (Deb11 -> Deb12), i found:
(venv) mailman@bywater:~$ pip install --force-reinstall mailman Traceback (most recent call last): File "/opt/mailman/venv/bin/pip", line 5, in <module> from pip._internal.cli.main import main ModuleNotFoundError: No module named 'pip'
I'm a bit stuck here. I usually do not work with python, so i do not know how to proceed. Any hints?
TIA QNo
On Thu, Aug 20, 2026 at 7:20 PM Christian H. Kuhn via Mailman-users < mailman-users@mailman3.org> wrote:
Hi all,
after upgrade from Ubuntu 25.10 (python3.13) to 26.04(python3.14) and
To upgrade a Python virtual environment, the right way would be to move the old venv aside (backup) and while at it also backup your DB(s), create a new venv from the new Python version and then install all the requirements.
PS: If you want to run MM3 with Python 3.13+, then your best bet is to install from gitlab as Python 3.13 still has some quirks which are only fixed in the yet to be released MM3 version.
-- Best regards, Odhiambo WASHINGTON, Nairobi,KE +254 7 3200 0004/+254 7 2274 3223 In an Internet failure case, the #1 suspect is a constant: DNS. "Oh, the cruft.", egrep -v '^$|^.*#' ¯\_(ツ)_/¯ :-) [How to ask smart questions: http://www.catb.org/~esr/faqs/smart-questions.html]
On 8/20/26 09:19, Christian H. Kuhn via Mailman-users wrote:
Hi all,
after upgrade from Ubuntu 25.10 (python3.13) to 26.04(python3.14) and
First and most importantly, Current Mailman does not support Python 3.14 because it depends on aiosmtpd and the current latest aiosmtpd 1.4.6 does not support Python 3.14. The GitHub branch at <https://github.com/aio-libs/aiosmtpd> does support Python 3.14, but it hasn't been released yet.
root@bywater ~ # python3 -m venv /opt/mailman/venv/
I don't understand. Are you creating a new venv? If so, you need to install Mailman in the new venv following <https://docs.mailman3.org/en/latest/install/virtualenv.html>.
If you do that, before installing Mailman in the venv, install aiosmtpd from github with
pip install git+https://github.com/aio-libs/aiosmtpd.git
You should probably also install Mailman core from gitlab with
pip install git+https://gitlab.com/mailman/mailman.git
minutely: Traceback (most recent call last): File "/opt/mailman/venv/bin/mailman-web", line 3, in <module> from mailman_web.manage import main ModuleNotFoundError: No module named 'mailman_web'
root@bywater /opt/mailman/venv/bin # ll mailm* -rwxr-xr-x 1 mailman www-data 204 Nov 5 2025 mailman* -rwxr-xr-x 1 mailman www-data 203 Nov 5 2025 mailman-web*
No module named 'mailman_web' is referring to /opt/mailman/venv/lib/python3.14/site-packages/mailman_web. Your installation is probably in /opt/mailman/venv/lib/python3.13/site-packages/
I don't understand what you have started with and what you have done. If you had a working Mailman in a venv with Python 3.13, I think the best approach would have been to install Python 3.13 along side Python 3.14, and you may still be able to do that.
If you want to proceed with Python 3.14, I think you need to create a new venv with Python 3.14 and first install aiosmtp from GitHub as above and then maybe mailman from GitLab as above
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
participants (3)
-
Christian H. Kuhn -
Mark Sapiro -
Washington Odhiambo