Here’s a helpful bit for MySQL users for whom the service starts and shuts down immediately. After updating a few things on my Mac, MySQL started misbehaving - I ran it, the service started, and it stopped itself a second later. This is what my console looks like:
hydra:~ ricardo$ sudo /sw/bin/mysqld_safe
Password:
Starting mysqld daemon with databases from /sw/var/mysql
STOPPING server from pid file /sw/var/mysql/hydra.pid
070527 19:24:42 mysqld ended
Explicitly stating the user fixed the problem:
hydra:~ ricardo$ sudo /sw/bin/mysqld_safe --user=root