Error when project compile

[OpakAlex]

When I run project, I get this error:
/Users/alexopak/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- xcodeproj (LoadError)

I install gem xcodeproj, but error not done.

How I could use rvm to compile project?

[OpakAlex]

fix this:
rvm default ruby-1.9.3-p194
sudo gem install xcodeproj