Odhiambo Washington writes:
Can you possibly blow away everything and start afresh again - using the following howto - https://wiki.list.org/DOC/Howto_Install_Mailman3_On_Debian10 ?
I appreciate your efforts to help, and with a different set of facts your approach *would* be helpful. So don't stop! But please be more careful. Sascha already has successfully installed Mailman (in fact more times than they know :-), has experience with this particular approach to installation, and was already interacting with two core developers. Starting from scratch at this point doesn't make sense.
After this, I deleted the venv again and startet anew, again.
Unknown to Sascha, this venv was already a successful install. The error messages can be ignored.
pip install wheel
But this time, I explicitly did (as Stephen suggested above) prior to
pip install wheel mailman psycopg2-binary\<2.9
This time, it ran through without errors, although "wheel" is also contained in the latter command. Can you explain that?
Note: this second run is also successful.
Explanation: "Failed to build wheel" is actually not an error. *wheels* are the preferred packaging format for Python for several years now, but others are available, and pip used one of those instead. I suspect the "Error" tag comes from a separate external command (bdist_wheel), but pip reads the error status and tries an alternative method to build a package.
Sascha: I don't understand why pip doesn't install wheel before starting on mailman in "pip wheel mailman psycopg2-binary\<2.9. I think that's a bug, because this is an obvious way to use pip. Perhaps you have an older version of pip? Have you tried pip install --upgrade pip?
Second question: There is still no directory "/etc/mailman3" created, where I can create mailman.cfg in.
That's right. There are a number of different philosophies about handling files like mailman.cfg, and the Mailman install scripts can't be sure which one you want to follow. /etc/mailman3/mailman.cfg probably works for 90% or 95% of installations nowadays, but we don't know. If you're not going to put mailman.cfg there, we shouldn't create the directory.
Does this maybe result from the fact that in first instance, I tried to install mailman3-full via "apt-get install" and removed it again via "apt-get remove"; with manually deleting /etc/mailman3 afterwards.
That's what I consider correct behavior as implemented by apt.
Shall I create /etc/mailman3 manually and adding "mailman" system user permissions?
Mark wrote earlier, but let me confirm that yes, that's what you should do. Note that Debian and Ubuntu prefer to gather all possible mailing list users into a single user 'list'. I don't think this causes trouble for Mailman, but in many cases if you create a different user (as you will if you follow our instructions), you will have problems if the system-created directory with system-standard owner and permissions is left behind. This is one of several reasons why you should purge (not just delete) packages supplied by distros if you are going to switch to upstream's code. (Obviously keep copies!)
Regards, Steve