package mysql-server-5.6 5.6.23-1~exp1~ubuntu3 failed to install/upgrade: subprocess installed post-removal script returned error exit status 1

[Shevek]

This bug was generated by an automatic process. The real bug is here, and should be merged:

https://bugs.launchpad.net/ubuntu/+source/mysql-5.6/+bug/1435080

ProblemType: Package
DistroRelease: Ubuntu 15.04
Package: mysql-server-5.6 5.6.23-1~exp1~ubuntu3
ProcVersionSignature: Ubuntu 3.19.0-9.9-generic 3.19.1
Uname: Linux 3.19.0-9-generic x86_64
ApportVersion: 2.16.2-0ubuntu4
AptOrdering: mysql-server-5.6: Remove
Architecture: amd64
Date: Sun Mar 22 14:30:24 2015
DpkgTerminalLog:
 Removing mysql-server-5.6 (5.6.23-1~exp1~ubuntu3) ...
 update-alternatives: using /etc/mysql/my.cnf.fallback to provide /etc/mysql/my.cnf (my.cnf) in auto mode
 /usr/bin/deb-systemd-helper: error: unable to link /etc/systemd/system/mysql.service to /dev/null: File exists
DuplicateSignature: package:mysql-server-5.6:5.6.23-1~exp1~ubuntu3:subprocess installed post-removal script returned error exit status 1
ErrorMessage: subprocess installed post-removal script returned error exit status 1
InstallationDate: Installed on 2015-03-05 (17 days ago)
InstallationMedia: Xubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
RelatedPackageVersions:
 dpkg 1.17.24ubuntu1
 apt 1.0.9.3ubuntu1
SourcePackage: mysql-5.6
Title: package mysql-server-5.6 5.6.23-1~exp1~ubuntu3 failed to install/upgrade: subprocess installed post-removal script returned error exit status 1
UpgradeStatus: Upgraded to vivid on 2015-03-19 (3 days ago)

[Shevek (r-launchpad-anarres-org)]

root@raven:~# sudo apt-get purge mysql-server-5.6 mysql-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'mysql-server' is not installed, so not removed
The following packages will be REMOVED:
  mysql-server-5.6
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 52.4 MB disk space will be freed.
Do you want to continue? [Y/n]
(Reading database ... 231499 files and directories currently installed.)
Removing mysql-server-5.6 (5.6.23-1~exp1~ubuntu3) ...
/usr/bin/deb-systemd-helper: error: unable to link /etc/systemd/system/mysql.service to /dev/null: File exists
dpkg: error processing package mysql-server-5.6 (--remove):
 subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
 mysql-server-5.6
E: Sub-process /usr/bin/dpkg returned an error code (1)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[David (daharper)]

This is a real pain, can't move forwards, can't move backwards. System is borked.

[cooolman (coolman)]

the same, I can not install the package, not I can not remove a package

[cooolman (coolman)]

Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'mysql-server' is not installed, so not removed
The following packages were automatically installed and are no longer required:
  mysql-client-5.6 mysql-client-core-5.6 mysql-server-core-5.6
Use 'apt-get autoremove' to remove them.
The following packages will be REMOVED:
  mysql-server-5.6
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 50.8 MB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 85533 files and directories currently installed.)
Removing mysql-server-5.6 (5.6.23-1~exp1~ubuntu3) ...
/usr/bin/deb-systemd-helper: error: unable to link /etc/systemd/system/mysql.service to /dev/null: File exists
dpkg: error processing package mysql-server-5.6 (--remove):
 subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
 mysql-server-5.6
E: Sub-process /usr/bin/dpkg returned an error code (1)

[cooolman (coolman)]

150323 14:02:18 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
150323 14:03:07 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
/usr/sbin/mysqld: Can't read dir of '/etc/mysql/mysql.conf.d/' (Errcode: 13 - Permission denied)
Fatal error in defaults handling. Program aborted

[aktiwers (aktiwers)]

I wrote the comment below on the duplicate bug here:
https://bugs.launchpad.net/ubuntu/+source/mysql-5.6/+bug/1435080/

I will repost it here if it helps anyone.

Got it fixed - first I followed this:
https://bugs.launchpad.net/ubuntu/+source/mysql-5.6/+bug/1435080/comments/11

It didnt work alone - but after deleting this file:
sudo rm /etc/systemd/system/mysql.service

And :
sudo apt-get purge mysql-server-5.6 mysql-server

I could remove it and then install it again:
sudo apt-get install mysql-server-5.6 mysql-server

[Nayar Joolfoo (nayar)]

It also prevents mariadb from installing or unistalling