title: " ERROR: Failed to build gem native extension " in 16.04
body: <p>I was trying to install Sass. Went through this guide to install Ruby which <a href="http://sass-lang.com/install" rel="nofollow noreferrer">Sass website</a> told is a pre-requisite </p>
  
  <p><a href="https://www.digitalocean.com/community/tutorials/how-to-install-ruby-and-set-up-a-local-programming-environment-on-ubuntu-16-04" rel="nofollow noreferrer">https://www.digitalocean.com/community/tutorials/how-to-install-ruby-and-set-up-a-local-programming-environment-on-ubuntu-16-04</a></p>
  
  <p>Looks like it went well</p>
  
  <pre><code>$ ruby -v
  ruby 2.3.1p112 (2016-04-26) [x86_64-linux-gnu]
  </code></pre>
  
  <p>Now I am stuck at this point. I am not sure how to proceed further. I am using Ubuntu 16.04</p>
  
  <pre><code>$ sudo gem install sass
  Building native extensions.  This could take a while...
  ERROR:  Error installing sass:
      ERROR: Failed to build gem native extension.
  
      current directory: /var/lib/gems/2.3.0/gems/ffi-1.9.18/ext/ffi_c
  /usr/bin/ruby2.3 -r ./siteconf20171122-3627-1olbmft.rb extconf.rb
  mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h
  
  extconf failed, exit code 1
  
  Gem files will remain installed in /var/lib/gems/2.3.0/gems/ffi-1.9.18 for inspection.
  Results logged to /var/lib/gems/2.3.0/extensions/x86_64-linux/2.3.0/ffi-1.9.18/gem_make.out
  </code></pre>
  
  <p>What should I do now ? Please help.</p>