I am getting the following error:
Loading development environment (Rails 2.2.2)
/opt/ruby-enterprise-1.8.6-20080709/lib/ruby/1.8/irb/completion.rb:10:in `require': no such file to load -- readline (LoadError)
The readline module is normally part of the Ruby package itself.
Did you manually build your Ruby install? If so, you want to make sure libreadline and its headers are installed, and build again.
apt-get install libreadline-dev
Or on RHEL/CentOS, try
yum install readline-devel
You are using a very old release of Ubuntu. If you want to keep using it, open
/etc/apt/sources.list in a text editor, and change all occurrences of
old-releases.ubuntu.com. Then, run
apt-get update and try the above again.
I urge you to consider updating your installation, though. Ubuntu 7.10 hasn't seen security updates in quite a while, and using it in production is not recommended. Even if it's not a production machine, there's a good chance you'll run into further problems because of old versions of certain libraries/dependencies.