title: RoR Precompiling Assets fail while rake assets:precompile - on basically empty application.js
body: <p>Running:</p>
  
  <pre><code>bundle exec rake assets:precompile RAILS_ENV=production --trace
  
  ** Execute assets:precompile:primary
  rake aborted!
  TypeError: Object doesn't support this property or method
    (in C:/Sites/MyApp/app/assets/javascripts/application.js)
  </code></pre>
  
  <p>Here is the entire content of <code>application.js</code>:</p>
  
  <pre><code>//= require jquery
  //= require jquery_ujs
  //= require_tree .
  </code></pre>
  
  <p>nothing else there. </p>
  
  <p>I tried to remove the three  <code>//= require</code> lines from <code>application.js</code>, the precompilation then runs with no problems.</p>