title: Install therubyracer gem on OSX 10.11 El Capitan
body: <p><code>bundle install</code> fails with <code>Make sure that `gem install therubyracer -v '0.12.1'` succeeds before bundling</code></p>
  
  <p><code>gem install therubyracer -v '0.12.1'</code> fails with errors which appear to relate to compilation</p>
  
  <p>Prior to this, libv8 gem was having problems but that is now installed thanks to following SO posts.</p>
  
  <p>Guides for fixing rubyracer for <a href="https://stackoverflow.com/questions/19630154/gem-install-therubyracer-v-0-10-2-on-osx-mavericks-not-installing">Mavericks</a> seem to not work, due to changes in El Capitan?</p>
  
  <pre><code>ln: /usr/bin/cpp: Operation not permitted 
  </code></pre>