title: ERROR: Currently 'rvm docs ...' does not work with non-rvm rubies
body: <p>I'm just starting to learn ruby/rails and I have followed the instructions to install ruby on OSX lion from <a href="http://pragmaticstudio.com/blog/2010/9/23/install-rails-ruby-mac" rel="nofollow">pragmaticstudio.com</a></p>
  
  <p>I have now got ruby 1.9.2 and 1.9.3 installed on my MacBook. However when I try and generate the documentation using:</p>
  
  <pre><code>sudo rvm docs generate
  </code></pre>
  
  <p>I get the error:</p>
  
  <pre><code>ERROR: Currently 'rvm docs ...' does not work with non-rvm rubies.
  </code></pre>
  
  <p>Has anyone else seen this, is there something obvious that I'm missing?</p>
  
  <p>The actual steps I took to install ruby was:</p>
  
  <ol>
  <li>sudo rvm install 1.9.3</li>
  <li>sudo rvm use 1.9.3</li>
  <li>sudo ruby -v   prints ruby 1.9.3dev (2011-07-31 revision 32789) [x86_64-darwin11.2.0]</li>
  <li>ruby -v        prints ruby 1.9.3dev (2011-07-31 revision 32789) [x86_64-darwin11.2.0]</li>
  <li>sudo rvm --default 1.9.3</li>
  <li>Then I try and run "sudo rvm docs generate" but I get the error about non-rvm ruby</li>
  </ol>
  
  <p>Thanks
  Alan.</p>