title: rake assets precompile failed
body: <p>When I run <code>bundle exec rake assets:precompile --trace</code>, my precompilation fails but I cannot see any specific reason for it.</p>
  
  <p>See this pastebin for my output: <a href="http://pastebin.com/zggZyPyM" rel="noreferrer">http://pastebin.com/zggZyPyM</a></p>