вроде все поставил нормально, но при вводе команды compass выдает вот такое:

compass
/usr/lib/ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find compass (>= 0) amongst [actionmailer-3.2.5, actionpack-3.2.5, activemodel-3.2.5, activerecord-3.2.5, activeresource-3.2.5, activesupport-3.2.5, arel-3.0.2, builder-3.0.0, bundler-1.1.4, erubis-2.7.0, hike-1.2.1, i18n-0.6.0, journey-1.0.3, json-1.7.3, mail-2.4.4, mime-types-1.18, multi_json-1.3.6, polyglot-0.3.3, puma-1.3.1, rack-1.4.1, rack-cache-1.2, rack-ssl-1.3.2, rack-test-0.6.1, rails-3.2.5, railties-3.2.5, rake-0.9.2.2, rdoc-3.12, rubygems-bundler-1.0.2, rvm-1.11.3.3, sprockets-2.1.3, thor-0.15.2, tilt-1.3.3, treetop-1.4.10, tzinfo-0.3.33] (Gem::LoadError)
from /usr/lib/ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'
from /usr/lib/ruby/1.9.1/rubygems.rb:1210:in `gem'
from /usr/local/bin/compass:18:in `'