Installing gems on passenger rails site

I just created a new server running a rails app using the wonderful Passenger plugin. 

After I’d install all the gems needed, I still got errors like :
“no such file to load — RMagick (MissingSourceFile)”

I tried doing a:
require ‘RMagick’

in both IRB and the console and here it loaded fine. Then I suddenly remembered the last time I installed a server (I quickly forget silly errors since it’s so easy to just google them), so I thought I’d post the solution here if I ever forgot it again.

The problem is that I’m also using the Ruby Enterprise Edition and all the gems had been installed to the “old” Ruby version. Not the Enterprise Edition. So installing the gems using the gem binary that lies under the Ruby Enterprise Edition fixed the error:

sudo /opt/ruby-enterprise-1.8.6-20090113/bin/gem install rmagick

(remember to update to the correct version)

Won’t forget that again.