If you are seeing this error on starting rails 3.x application, Change the below in your gem file
gem 'compass',:git => "git://github.com/chriseppstein/compass.git"
to
gem 'compass-rails'
If you are seeing this error on starting rails 3.x application, Change the below in your gem file
gem 'compass',:git => "git://github.com/chriseppstein/compass.git"
to
gem 'compass-rails'