We're looking for long answers that provide some explanation and context.
Don't just give a one-line answer; explain why your answer is right, ideally with citations.
Just run the app on your disk, restart, and try again.
The solution that worked for me was here: https://serverfault.com/questions/334284/cant-create-pid-file-on-mysql-server-permission-denied Changing some of my permissions seemed to do the trick.
I'm running a Mid-2012 Macbook Air with OS X 10.8.2 and mysql was installed with homebrew. Please take note that you need to run mysql_install_db from the with top level of the mysql directory (IE, usr/local/Cellar/mysql/5.5.25).
So a note to anyone else passing by; don't try to cheat the brew doctor and think you know better! When I tried to start up mysql I got a message: The server quit without updating PID file.
Go to lampp/var/ and do chown -R mysql mysql/ That worked for me!
Search for updating pid:
Answers that don't include explanations may be removed.