Ubuntu – Partial upgrade – why remove MariaDB

mariadbMySQLupgrade

My 12.04 system wants to run a partial upgrade, as part of which it proposes to remove certain MariaDB packages (see screenshot below). Attached is my sources.list file – I don't understand why the system should be proposing the removal of the MariaDB packages, given I have explicitly chosen MariaDB as a replacement for MySQL?

enter image description here

clive@cooler-master:~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423)]/ precise main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise universe
deb http://gb.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://gb.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe
deb http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src http://security.ubuntu.com/ubuntu precise-security multiverse

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.
deb http://extras.ubuntu.com/ubuntu precise main
deb-src http://extras.ubuntu.com/ubuntu precise main

# MariaDB 5.5 repository list - created 2012-09-21 09:23 UTC
# http://downloads.mariadb.org/mariadb/repositories/
deb http://ftp.heanet.ie/mirrors/mariadb/repo/5.5/ubuntu precise main
deb-src http://ftp.heanet.ie/mirrors/mariadb/repo/5.5/ubuntu precise main

# deb http://repository.spotify.com stable non-free

deb http://deb.opera.com/opera/ stable non-free

deb http://ppa.launchpad.net/yorba/ppa/ubuntu precise main
deb-src http://ppa.launchpad.net/yorba/ppa/ubuntu precise main

Best Answer

MariaDB cover this in their article on installing deb packages, best way to fix it is by pinning the MariaDB repo. Which you can do by following these instructions: https://mariadb.com/kb/en/installing-mariadb-deb-files/#pinning-the-mariadb-repository (if you scroll up they also explain why it happens)