[Pkg-mailman-hackers] Bug#920304: mailman3-web: mailman3web / django does not like python3-pymysql

[Bjoern Franke]

Package: mailman3-web
Version: 0+20180916-2~bpo9+1
Severity: grave
Justification: renders package unusable

Dear Maintainer,

upgrading mailman3-web lead to
  File
  "/usr/lib/python3/dist-packages/django/db/backends/mysql/base.py",
  line 30, in <module>
      'Did you install mysqlclient or MySQL-python?' % e
      django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb
      module: No module named 'MySQLdb'.
      Did you install mysqlclient or MySQL-python?

Somehow python3-pymysql does not provide the required module.


-- System Information:
Debian Release: 9.7
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'proposed-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

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

Versions of packages mailman3-web depends on:
ii  dbconfig-sqlite3           2.0.8
ii  debconf [debconf-2.0]      1.5.61
ii  lsb-base                   9.20161125
ii  node-less                  1.6.3~dfsg-2
ii  python3                    3.5.3-1
ii  python3-django-hyperkitty  1.2.1-4~bpo9+1
ii  python3-django-postorius   1.2.2-4~bpo9+2
ii  python3-psycopg2           2.6.2-1
ii  python3-pymysql            0.7.10-1
ii  python3-whoosh             2.7.0-2
ii  ruby-sass                  3.4.23-1
ii  ucf                        3.0036
ii  uwsgi                      2.0.14+20161117-3+deb9u2
ii  uwsgi-plugin-python3       2.0.14+20161117-3+deb9u2

Versions of packages mailman3-web recommends:
ii  nginx               1.10.3-1+deb9u2
ii  nginx-full [nginx]  1.10.3-1+deb9u2

Versions of packages mailman3-web suggests:
pn  postgresql | default-mysql-server | virtual-mysql-server  <none>

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

-- debconf information:
  mailman3-web/install-error: abort
  mailman3-web/remote/host: localhost
  mailman3-web/emailname: localhost.local
  mailman3-web/pgsql/method: TCP/IP
  mailman3-web/pgsql/authmethod-admin: ident
  mailman3-web/pgsql/no-empty-passwords:
  mailman3-web/remote/newhost:
  mailman3-web/configure-webserver: none
  mailman3-web/mysql/admin-user:
  mailman3-web/missing-db-package-error: abort
  mailman3-web/remote/port:
  mailman3-web/internal/reconfiguring: false
  mailman3-web/restart-webserver: true
  mailman3-web/dbconfig-upgrade: true
  mailman3-web/django-site: lists.ffnw.de
  mailman3-web/nginx-choice:
  mailman3-web/db/app-user: mailman3web at localhost
  mailman3-web/db/dbname: mailman3web
  mailman3-web/db/basepath: /var/lib/mailman3/web
  mailman3-web/dbconfig-reinstall: false
  mailman3-web/upgrade-backup: true
  mailman3-web/database-type:
  mailman3-web/upgrade-error: abort
  mailman3-web/superuser-mail: root at localhost
  mailman3-web/internal/skip-preseed: false
  mailman3-web/pgsql/manualconf:
  mailman3-web/purge: false
  mailman3-web/pgsql/authmethod-user: password
  mailman3-web/dbconfig-remove: true
  mailman3-web/remove-error: abort
* mailman3-web/dbconfig-install: false
  mailman3-web/pgsql/admin-user: postgres
  mailman3-web/mysql/method: Unix socket
  mailman3-web/pgsql/changeconf: false
  mailman3-web/passwords-do-not-match:
  mailman3-web/superuser-name: admin