[Pkg-mailman-hackers] Bug#873505: mailman: Runner crashes when processing incoming email

[Pete Donnell]

Package: mailman
Version: 1:2.1.23-1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

Mailman was installed following these instructions under Debian Jessie:
https://alephnull.uk/howto-mailman-debian-jessie-apache-postfix-spamassassin-virtualhost

All worked well. The server was upgraded to Debian Stretch a couple of weeks ago,
and since then no messages have got through to the mailing lists. No errors or bounceback
messages are generated. I only became aware of the problem when users complained that
their lists weren't working anymore. The only evidence I've found is this snippet from
/var/log/mailman/error:

Aug 21 21:38:32 2017 (1405) Uncaught runner exception: cannot import name matches_p
Aug 21 21:38:32 2017 (1405) Traceback (most recent call last):
  File "/var/lib/mailman/Mailman/Queue/Runner.py", line 119, in _oneloop
    self._onefile(msg, msgdata)
  File "/var/lib/mailman/Mailman/Queue/Runner.py", line 190, in _onefile
    keepqueued = self._dispose(mlist, msg, msgdata)
  File "/var/lib/mailman/Mailman/Queue/IncomingRunner.py", line 130, in _dispose
    more = self._dopipeline(mlist, msg, msgdata, pipeline)
  File "/var/lib/mailman/Mailman/Queue/IncomingRunner.py", line 150, in _dopipeline
    __import__(modname)
  File "/var/lib/mailman/Mailman/Handlers/SpamAssassin.py", line 31, in <module>
    from Mailman.Handlers.Moderate import matches_p
ImportError: cannot import name matches_p

I've searched the internet for people reporting the same problem and not come across
anything. Without a better knowledge of the internals of Mailman I can't debug it
further myself.

Thanks,
Pete

-- System Information:
Debian Release: 9.1
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-3-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages mailman depends on:
ii  apache2 [httpd]        2.4.25-3+deb9u2
ii  cron [cron-daemon]     3.0pl1-128+b1
ii  debconf [debconf-2.0]  1.5.61
ii  libc6                  2.24-11+deb9u1
ii  logrotate              3.11.0-0.1
ii  lsb-base               9.20161125
ii  python                 2.7.13-2
ii  python-dnspython       1.15.0-1
ii  ucf                    3.0036

Versions of packages mailman recommends:
ii  postfix [mail-transport-agent]  3.1.4-7

Versions of packages mailman suggests:
pn  listadmin     <none>
ii  lynx          2.8.9dev11-1
ii  spamassassin  3.4.1-6

-- debconf information:
* mailman/site_languages: en
  mailman/queue_files_present: abort installation
* mailman/create_site_list:
* mailman/used_languages: en
* mailman/default_server_language: en