guardian/frontend — pull request #2835 by rtyley (2014-01-22 14:38:47+00:00)
Title: Recommend installing 'ruby-dev' on Ubuntu

sudo gem install ffi -v '1.9.3'

...was failing

http://stackoverflow.com/questions/18316667/failed-to-build-gem-native-extension-mkmf-loaderror-ubuntu-12-04/18316692#18316692