[Pkg-mailman-hackers] Bug#1053502: mailman3-web: Package failed to install during upgrade from Debian 11 to 12

[Steven Verhulst]

Package: mailman3-web
Version: 0+20200530-2.1
Severity: important

Dear Maintainer,

When we upgraded our test mailingserver from Debian 11 to 12 we noticed the following error:

Setting up mailman3-web (0+20200530-2.1) ...
Determining localhost credentials from /etc/mysql/debian.cnf: failed (hosts not equal).
dbconfig-common: writing config to /etc/dbconfig-common/mailman3-web.conf
dbconfig-common: flushing administrative password
sed: -e expression #2, char 82: unterminated `s' command
dpkg: error processing package mailman3-web (--configure):
installed mailman3-web package post-installation script subprocess returned error exit status 1

>From what I understand there seems to be an issue with the post-installation script.

Since the post-installation script did not run it left us with a broken listserver.
Further it is not possible to use APT to update packages as it keep warning about mailman3-web package being broken.

-- System Information:
Debian Release: 12.1
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-12-amd64 (SMP w/2 CPU threads; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages mailman3-web depends on:
ii  dbconfig-sqlite3           2.0.24
ii  debconf [debconf-2.0]      1.5.82
ii  init-system-helpers        1.65.2
ii  lsb-base                   11.6
ii  python3                    3.11.2-1+b1
ii  python3-django-hyperkitty  1.3.7-1
ii  python3-django-postorius   1.3.8-3
ii  python3-mysqldb            1.4.6-2+b1
ii  python3-psycopg2           2.9.5-1+b1
ii  python3-whoosh             2.7.4+git6-g9134ad92-7
ii  sysvinit-utils [lsb-base]  3.06-4
ii  ucf                        3.0043+nmu1
ii  uwsgi-core                 2.0.21-5.1
ii  uwsgi-plugin-python3       2.0.21-5.1

Versions of packages mailman3-web recommends:
ii  libapache2-mod-proxy-uwsgi  2.4.57-2

Versions of packages mailman3-web suggests:
ii  mariadb-server [virtual-mysql-server]  1:10.11.3-1

-- Configuration Files:
/etc/mailman3/apache.conf changed [not included]
/etc/mailman3/uwsgi.ini changed [not included]

-- debconf information excluded