It appear you havent told rvm what ruby to use and you are currently in the system default which does not have the required gems installed, try doing
rvm use 1.9.2 then rails -v -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.

