title: Rails console 'y' helper returns NameError rather than yaml-formatting output
body: <p>I'm trying to use <code>y object</code> in Rails 3.2.6/Ruby 1.9.3 console to get nicely formatted yaml output for an ActiveRecord object, but for some reason it isn't working for me. I've used it in the past, but somewhere along the way it broke. I get the following output when I try:</p>
  
  <pre><code>NameError: undefined local variable or method `yaml' for main:Object
  </code></pre>