[debian-mysql] Bug#789589: Bug#789589: mariadb-server-10.0: Infinite upgrade

[Otto Kekäläinen]

Basically what you Yuril did was removed all configuration and data
files, and then installed. For some reason the mysqld daemon did not
start on your system, and the failure became visible during an upgrade
where the system restarts the service.

I broke one installation on purpose, and this is how it looks it dpkg
tries to restart MariaDB and it fails:
****************************************************************************
Unpacking mariadb-server (10.0.19-1) ...
Processing triggers for man-db (2.7.0.2-5) ...
Setting up mariadb-server-core-10.0 (10.0.19-1) ...
Setting up mariadb-server-10.0 (10.0.19-1) ...
[ ok ] Stopping MariaDB database server: mysqld.
150703  1:06:44 [Note] /usr/sbin/mysqld (mysqld 10.0.19-MariaDB-1)
starting as process 16263 ...
[....] Starting MariaDB database server: mysqld . . . . . . . . . . .
. . . . . . . . . [FAIL . . . . . . . failed!
invoke-rc.d: initscript mysql, action "start" failed.
dpkg: error processing package mariadb-server-10.0 (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mariadb-server:
 mariadb-server depends on mariadb-server-10.0 (>= 10.0.19-1); however:
  Package mariadb-server-10.0 is not configured yet.

dpkg: error processing package mariadb-server (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 mariadb-server-10.0
 mariadb-server
E: Sub-process /usr/bin/dpkg returned an error code (1)
****************************************************************************

In these cases look at /var/log/mysql/error.log to figure out why the
server does not start. You can also manually run multiple times 'sudo
service mysql restart' to see if you fixed the configuration/data
problem.

Dpkg will not be able to recover from this automatically. It is by
design that dpkg ends up in a stuck state if package installations
(and the related install scripts) fail.