[Mailman-Users] mailman installation on ubuntu failing

Mark Sapiro mark at msapiro.net
Fri Jan 14 20:06:08 CET 2011

Noah wrote:
>I am having issues installing mailman on my ubuntu machine.  Its a 32bit 
>Processor so I am not sure why 64-amd version of mailman was ever 
>installed.  any clues on how to solve this problem?

I know nothing of various Debian packages but it doesnt appear to me
that this message is saying the current installed version is

>Preparing to replace mailman 1:2.1.9-9ubuntu1.1 (using 
>.../mailman_1%3a2.1.9-9ubuntu1.2_amd64.deb) ...

It looks to me like it is saying it is going to replace mailman
1:2.1.9-9ubuntu1.1 with the package from

In any case, the following is the issue

>Downgrade detected, from version 0x2010bf0 to version 0x20109f0
>This is probably not safe.

This is Mailman's bin/update which is the last step of the standard
installation process telling you that the previously installed Mailman
version (0x2010bf0) is 2.1.11 final and the one you are installing
over it (0x20109f0) is 2.1.9 final.

I don't know what the apt-get process does to undo what it had done up
to this point, but at this point, the new Mailman 2.1.9 had been
installed and all that was left to do was any necessary list data
migration. Since there aren't any data format changes between 2.1.9
and 2.1.11, it was essentially done.

If the installed package wasn't backed out, you can just manually run
Mailman's bin/update -f, but the real question is where did the 2.1.11
version come from and why doesn't apt-get know about it?

If I were you, I would look at Mailman's Mailman/Version.py file for
the version currently installed. If it is 2.1.11, then apt-get
reversed its changes, and what to do depends on whether you want to
leave 2.1.11 in place or overwrite it with 2.1.9. To leave it in
place, do nothing. You should be able to just start Mailman if it
isn't already running.

To overwrite 2.1.11 with 2.1.9, remove Mailman's
data/last_mailman_version file or edit its contents which are
apparently 0x2010bf0 to something like 0x20108f0 and then re-run the

On the other hand, if the version of Mailman's Mailman/Version.py file
is 2.1.9, then you have already over written the 2.1.11 version and
you can finish the process by stopping Mailman if it's running, then
run Mailman's

bin/update -f

and start Mailman.

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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