title: Rails 3.1 SASS asset helpers not not including RAILS_RELATIVE_URL_ROOT / relative_url_root
body: <p>I have been working on an upgrade to Rails 3.1 from 2.3.11. One of the main hurdles to clear is the conversion to the asset pipeline. In this process I decided to convert my css to sass (scss). In rails 3.1 all assets delivered through the pipeline receive a hash appended to the filename in production. Because of this, all the images referenced in my css now needed to use the image-path or image-url helpers in sass. The issue is, that even though I have set my ENV['RAILS_RELATIVE_URL_ROOT'] in my environment.rb file sass asset helper fail to include the relative_url_root.</p>
  
  <p>Just for clarity, to add the relative_url_root in rails 3.1, I added the following line to my environment.rb file:</p>
  
  <pre><code>ENV['RAILS_RELATIVE_URL_ROOT'] = '/foo'
  </code></pre>
  
  <p>and add the following line to my virtual host:</p>
  
  <pre><code>RailsBaseURI /foo
  </code></pre>
  
  <p>This strategy seems to work fine for all links and such. It is just the asset helpers in sass that don't seem to work properly. Any ideas would be appreciated.</p>