gem install rmagick Fetching: rmagick-2.13.4.gem (100%) Building native extensions. This could take a while... ERROR: Error installing rmagick: ERROR: Failed to build gem native extension. /home/vagrant/.rbenv/versions/2.2.0/bin/ruby -r ./siteconf20150313-7941-u2y4vg.rb extconf.rb checking for Ruby version >= 1.8.5... yes checking for gcc... yes checking for Magick-config... no checking for pkg-co