Starting nagios:CONFIG ERROR! Start aborted. Check your Nagios configuration.
This confused the crap out of me, mostly because of the lack of information in the error messages. So after a few hours of googling, I found that the problem was with SELinux. This is the fourth or fifth time that this piece of software has gotten in the way of installs. It’s no wonder then that the first piece of advice when telling someone on a forum/mailing list is to give the advice to set ‘SELINUX=disabled’.
This ofcourse ends up voiding any security advantage that SELinux may have had, but apparently everyone seems to think that Linux is secure enough.