irb: not found on script/console

I installed RoR on my machine, and everything seems to work fine,
except for the fact that i get this...

Loading development environment (Rails 2.0.2)
sh: irb: not found

...when i try to load the console.

Any ideas on what i should do to fix that?

install irb. If you’re running ubuntu it’s sudo apt-get install irb. If you’re running Gentoo it’s emerge irb.