[Pkg-mailman-hackers] Bug#921128: mailman3-web fails to initialize mysql: Specified key was too long

[Antoine Beaupre]

Package: mailman3-web
Version: 0+20180916-2~bpo9+1
Severity: grave

I can't seem to install mailman3-web, at least from backports:

Paramétrage de mailman3-web (0+20180916-2~bpo9+1) ...
Determining localhost credentials from /etc/mysql/debian.cnf: succeeded.
dbconfig-common: writing config to /etc/dbconfig-common/mailman3-web.conf
mailman3web already exists and has privileges on mailman3web.
creating database mailman3web: already exists.
dbconfig-common: flushing administrative password
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/lib/python3/dist-packages/django/db/backends/mysql/base.py", line 101, in execute
    return self.cursor.execute(query, args)
  File "/usr/lib/python3/dist-packages/MySQLdb/cursors.py", line 226, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib/python3/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorvalue
  File "/usr/lib/python3/dist-packages/MySQLdb/cursors.py", line 217, in execute
    res = self._query(query)
  File "/usr/lib/python3/dist-packages/MySQLdb/cursors.py", line 378, in _query
    rowcount = self._do_query(q)
  File "/usr/lib/python3/dist-packages/MySQLdb/cursors.py", line 341, in _do_query
    db.query(q)
  File "/usr/lib/python3/dist-packages/MySQLdb/connections.py", line 280, in query
    _mysql.connection.query(self, query)
_mysql_exceptions.OperationalError: (1071, 'Specified key was too long; max key length is 767 bytes')

That's after stumbling upon bug #919145, so I just had installed mysqldb and
pymysql. I tried purging (deleting databases and creds) the package and
reinstalling, with a similar result.

That's a rather strange error - a 767 bytes key does seem very long. ;) I
suspect something might be going on in dbconfig-common - the mailman postinst
doesn't seem to have anything specific to this, for example. Note that
dbconfig-common was upgraded to backports as a dependency, so this might be
where the trouble lies as well.

Unfortunately, I have about zero clue how to debug dbconfig, which has always
been a horrible black box to me, so I am sorry I cannot help further. 

-- System Information:
Debian Release: 9.7
  APT prefers stable
  APT policy: (500, 'stable'), (1, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-8-amd64 (SMP w/2 CPU cores)
Locale: LANG=fr_CA.UTF-8, LC_CTYPE=fr_CA.UTF-8 (charmap=UTF-8), LANGUAGE=fr_CA.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           2.0.11~bpo9+1
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                  3.5.3-1~bpo9+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  libapache2-mod-proxy-uwsgi  2.0.14+20161117-3+deb9u2
ii  nginx                       1.10.3-1+deb9u2
ii  nginx-full [nginx]          1.10.3-1+deb9u2

Versions of packages mailman3-web suggests:
ii  mariadb-server-10.1 [virtual-mysql-server]  10.1.37-0+deb9u1

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