Strange error with script/console

Hello,

I get this:
$ ./script/console
Loading development environment.
/usr/local/lib/ruby/1.8/irb/completion.rb:10:in `require': no such
file to load -- readline (LoadError)
...

found a LOT of solutions via google, like
$ apt-get install libncurses5-dev libreadline5-dev

but since I use RedHat this doesn't work for me.
also tried
$ yum install ncurses-devel readline-devel
without success (ncurses-devel worked, readline-devel failed)

Does anyone know what I could do?
Is it necessary to recompile ruby? :frowning:

Thanks in advance,
Paul