I found this for some reason on my Digital Ocean droplet when trying to install mysql. The server would be placed in this broken state all due to the root password of the server failing. Fortunately some trial and error found a solution. I followed along with this tutorial for the most part.
I also noticed when the installation did complete it said MySQL was running on a 14.04.1 server, which is not true...I do not know why this appears but I suspect maybe there is some kind of unknown permissions bug with MySQL at the moment and 14.04.3
Basically its the usual sudo apt-get install mysql-server as given in the link above except when it does prompt for the root password leave it blank...DO NOTHING. let the software install itself.
Then we hit the setup scripts. And these are your saviours
After instalation completes. Run this guy:
Then run this guy:
Within this second script you will be prompted with the option to reset the root password. At THIS point change the root password to what you would like. And you will have no errors
I don't know if it actually have any effect whatsoever but I also have mongodb running on the same server. So I also had it turned off while this whole installation process occurred in case it interfered. If you have issues still with the above and have mongo installed, try that aswell
sudo service mongod stop #turn off mongo sudo service mongod start #turn on mongo