title: Error: Failed to build gem native extension (can't find header files for ruby.h)
body: <p>I'm trying to install <code>azure_mgmt_storage</code> on Ubuntu 14.04.5 LTS. (And I'm new to Linux and Ruby.) Here's the command I tried:</p>
  
  <pre><code>sudo gem install azure_mgmt_storage
  Building native extensions. This could take a while...
  ERROR:  Error installing azure_mgmt_storage:
      ERROR: Failed to build gem native extension.
  
  current directory: /var/lib/gems/2.4.0/gems/unf_ext-0.0.7.5/ext/unf_ext
  /usr/bin/ruby2.4 -r ./siteconf20180221-102454-dq4ty1.rb extconf.rb
  mkmf.rb can't find header files for ruby at /usr/lib/ruby/include/ruby.h
  </code></pre>
  
  <p>I've have Rails 4.02 installed, and Ruby 2.4.3p205 (2017-12-14 revision 61247).
  Based on another post, I also ran these:</p>
  
  <pre><code>sudo apt-get install ruby-dev
  sudo apt-get install ruby2.0-dev
  sudo apt-get install ruby2.2-dev
  sudo apt-get install ruby2.3-dev
  </code></pre>
  
  <p>How do I get ruby.h installed?
  Thanks!</p>