I\'ve been working through the Rails install instructions (http://railsapps.github.io/installrubyonrails-mac.html) and everything was okay up until I got to gem instal
I had the same issue, on Debian it seemed only a problem of missing 'dev' libraries, probably needed to compile sources during installation (I'm guessing). I solved it by installing (via apt-get or aptitude) the following packages: