Hello iahve just installed Ruby grom sources. Here i a command I have 
executed:
$ruby -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-linux]

Unfortunately I am not able to start up the irb:
$irb -v
/usr/bin/irb:10:in `require': no such file to load -- irb (LoadError)
         from /usr/bin/irb:10

Yhe irb. rb is available undet the following directory:
$find / -name irb.rb
/lib/ruby/1.8/irb.rb

What should I to addjust? How the ruby searches when looking for 
libraris i.e. irb.rb or socket.rb? How to fix the problem?

Regards,
FO