我正在尝试在 irb 中测试 scrobbler/scrobbler2 gem (http://scrobbler.rubyforge.org/)。我遇到的问题是，每次我尝试在irb中运行它时，都会出现以下错误：
--
Loading development environment (Rails 2.3.9)
>> album = Scrobbler::Album.new('Carrie Underwood', 'Some Hearts', :include_info => true)
NameError: uninitialized constant Scrobbler from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.9/lib/active_support/dependencies.rb:469:in
`load_missing_constant' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.9/lib/active_support/dependencies.rb:106:in
`const_missing' from /usr/lib/ruby/gems/1.8/gems/activesupport-2.3.9/lib/active_support/dependencies.rb:118:in `const_missing'
--
我不明白这个错误，有人能指出我正确的方向吗？
非常感谢！！