Gem files will remain installed in /var/www/demo/vendor/bundle/ruby/2.2.0/gems/nokogiri-1.6.6.2 for inspection. Results logged to /var/www/demo/vendor/bundle/ruby/2.2.0/extensions/x86_64-linux/2.2.0-static/nokogiri-1.6.6.2/gem_make.out An error occurred while installing nokogiri (1.6.6.2), and Bundler cannot continue. Make sure that `gem install nokogiri -v '1.6.6.2'` succeeds before bundling.