Does this error message look familar when you script/console?


$> script/console
Loading production environment (Rails 2.1.0)
/usr/lib/ruby/1.8/irb/completion.rb:10:in `require': no such file to load -- readline (LoadError)
from /usr/lib/ruby/1.8/irb/completion.rb:10
from /usr/lib/ruby/1.8/irb/init.rb:252:in `require'
from /usr/lib/ruby/1.8/irb/init.rb:252:in `load_modules'
from /usr/lib/ruby/1.8/irb/init.rb:250:in `each'
from /usr/lib/ruby/1.8/irb/init.rb:250:in `load_modules'
from /usr/lib/ruby/1.8/irb/init.rb:21:in `setup'
from /usr/lib/ruby/1.8/irb.rb:54:in `start'
from /usr/bin/irb:13

This happens when readline is somehow different than your current version of ruby or corrupted. The quick fix is to recompile readline. To do it in CentOS with yum:


$> yum install readline-devel -y
$> cd /root/src/ruby-1.8.6-p114/ext/readline/
$> ruby extconf.rb
$> make
$> sudo make install


Now you should have script/console working.

Source: http://web.elctech.com/2009/01/09/fixing-ruby-no-such-file-to-load-readline-error-in-centos/