title: No ruby-devel in RHEL7?
body: <p>I have a recently installed RHEL7 system, and need to do gem install jekyll, however this fails as:</p>
  
  <pre><code>Fetching: yajl-ruby-1.2.1.gem (100%)
  Building native extensions.  This could take a while...
  ERROR:  Error installing jekyll:
          ERROR: Failed to build gem native extension.
  
      /usr/bin/ruby extconf.rb
  mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h
  </code></pre>
  
  <p>Google suggest this is due to the lack of a ruby-devel package being installed. However there doesn't seem to <em>be</em> such a package in RHEL7. Do I need to move to a software collection (don't really want to do this as this will be for a production machine, not development) or can I get it some other way?</p>