Q:

Problems installing mysql on Ubuntu 14.04

I hit the following error shortly on entering the mysql "root" password:
An error occurred while setting the password for the MySQL administrative user. 
This may have happened because the account already has a password, or because of a
communication problem with the MySQL server.

Here is the full output of apt-get install mysql-server:
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libaio1 libdbd-mysql-perl libdbi-perl libmysqlclient18 libterm-readkey-perl
  mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server-5.5
  mysql-server-core-5.5
Suggested packages:
  libclone-perl libmldbm-perl libnet-daemon-perl libplrpc-perl
  libsql-statement-perl tinyca mailx
The following NEW packages will be installed:
  libaio1 libdbd-mysql-perl libdbi-perl libmysqlclient18 libterm-readkey-perl
  mysql-client-5.5 mysql-client-core-5.5 mysql-common mysql-server
  mysql-server-5.5 mysql-server-core-5.5
0 upgraded, 11 newly installed, 0 to remove and 49 not upgraded.
Need to get 0 B/8,797 kB of archives.
After this operation, 93.5 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Preconfiguring packages ...
Selecting previously unselected package libaio1:i386.
(Reading database ... 88930 files and directories currently installed.)
Preparing to unpack .../libaio1_0.3.109-4_i386.deb ...
Unpacking libaio1:i386 (0.3.109-4) ...
Selecting previously unselected package mysql-common.
Preparing to unpack .../mysql-common_5.5.40-0ubuntu0.14.04.1_all.deb ...
Unpacking mysql-common (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package libmysqlclient18:i386.
Preparing to unpack .../libmysqlclient18_5.5.40-0ubuntu0.14.04.1_i386.deb ...
Unpacking libmysqlclient18:i386 (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package libdbi-perl.
Preparing to unpack .../libdbi-perl_1.630-1_i386.deb ...
Unpacking libdbi-perl (1.630-1) ...
Selecting previously unselected package libdbd-mysql-perl.
Preparing to unpack .../libdbd-mysql-perl_4.025-1_i386.deb ...
Unpacking libdbd-mysql-perl (4.025-1) ...
Selecting previously unselected package libterm-readkey-perl.
Preparing to unpack .../libterm-readkey-perl_2.31-1_i386.deb ...
Unpacking libterm-readkey-perl (2.31-1) ...
Selecting previously unselected package mysql-client-core-5.5.
Preparing to unpack .../mysql-client-core-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...
Unpacking mysql-client-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package mysql-client-5.5.
Preparing to unpack .../mysql-client-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...
Unpacking mysql-client-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package mysql-server-core-5.5.
Preparing to unpack .../mysql-server-core-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...
Unpacking mysql-server-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Processing triggers for man-db (2.6.7.1-1) ...
Setting up mysql-common (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package mysql-server-5.5.
(Reading database ... 89293 files and directories currently installed.)
Preparing to unpack .../mysql-server-5.5_5.5.40-0ubuntu0.14.04.1_i386.deb ...
Unpacking mysql-server-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Selecting previously unselected package mysql-server.
Preparing to unpack .../mysql-server_5.5.40-0ubuntu0.14.04.1_all.deb ...
Unpacking mysql-server (5.5.40-0ubuntu0.14.04.1) ...
Processing triggers for man-db (2.6.7.1-1) ...
Processing triggers for ureadahead (0.100.0-16) ...
Setting up libaio1:i386 (0.3.109-4) ...
Setting up libmysqlclient18:i386 (5.5.40-0ubuntu0.14.04.1) ...
Setting up libdbi-perl (1.630-1) ...
Setting up libdbd-mysql-perl (4.025-1) ...
Setting up libterm-readkey-perl (2.31-1) ...
Setting up mysql-client-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Setting up mysql-client-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Setting up mysql-server-core-5.5 (5.5.40-0ubuntu0.14.04.1) ...
Setting up mysql-server-5.5 (5.5.40-0ubuntu0.14.04.1) ...
141117 20:53:10 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
start: Job failed to start
invoke-rc.d: initscript mysql, action "start" failed.
dpkg: error processing package mysql-server-5.5 (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mysql-server:
 mysql-server depends on mysql-server-5.5; however:
  Package mysql-server-5.5 is not configured yet.

dpkg: error processing package mysql-server (--configure):
 dependency problems - leaving unconfigured
Processing triggers for libc-bin (2.19-0ubuntu6.3) ...
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          Processing triggers for ureadahead (0.100.0-16) ...
Errors were encountered while processing:
 mysql-server-5.5
 mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

To completely uninstall mysql, I have run through the following steps:
sudo apt-get remove --purge mysql-server mysql-client mysql-common
sudo apt-get remove --purge mysql-server-core-5.5 mysql-client-core-5.5
sudo apt-get autoremove
sudo apt-get autoclean
sudo deluser mysql
sudo rm -rf /var/lib/mysql
sudo rm -rf /etc/mysql

This seems to completely remove everything, but subsequent installation attempts produce the same problem.  
I have also set permissions on /tmp.  
It may be of note that Postgres is installed on this machine, but from what I understand this should not be a problem.  
Thanks in advance for any help/suggestions.

A:

The key clue is probably this line in the output:
dpkg: dependency problems prevent configuration of mysql-server:
mysql-server depends on mysql-server-5.5; however:
Package mysql-server-5.5 is not configured yet.

Make sure MySQL is entirely removed/purged
sudo apt-get remove --purge mysql-server mysql-client mysql-common mysql-server-5.5 mysql-client-5.5 mysql-server-core-5.5 mysql-client-core-5.5
sudo apt-get autoremove
sudo apt-get autoclean
sudo rm -rf /var/lib/mysql /etc/mysql
sudo deluser mysql

sudo apt-get dist-upgrade
sudo reboot
sudo apt-get install mysql-server-5.5
sudo apt-get install mysql-server

