title: libxslt is missing while installing ruby gem nokogiri
body: <p>I recognize that this is a duplicate question however all the other answers I've found related to this issue have not seemed to help me...</p>
  
  <p>I'm installing <code>GitLab</code> and running through the gem dependencies when it hits the <code>NokoGiri</code> gem requirement and fails with the following info:</p>
  
  <pre><code>ERROR:  Error installing nokogiri:
  ERROR: Failed to build gem native extension.
  
  /usr/local/bin/ruby extconf.rb
  extconf.rb:10:in `&lt;main&gt;': Use RbConfig instead of obsolete and deprecated Config.
  extconf.rb:10:in `&lt;main&gt;': Use RbConfig instead of obsolete and deprecated Config. 
  extconf.rb:11:in `&lt;main&gt;': Use RbConfig instead of obsolete and deprecated Config.
  checking for libxml/parser.h... yes
  checking for libxslt/xslt.h... yes
  checking for libexslt/exslt.h... yes
  checking for iconv_open() in iconv.h... yes
  checking for xmlParseDoc()... -lxml2
  checking for xsltParseStylesheetDoc()... -lxslt
  -----
  libxslt is missing.  please visit http://nokogiri.org/tutorials/installing_nokogiri.html for help with installing dependencies.
  -----
  </code></pre>
  
  <p>So, this error leads me down the path of attempting to install <code>libxslt</code> with the following command:</p>
  
  <pre><code>$ sudo apt-get install libxslt-dev
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  Note, selecting 'libxslt1-dev' instead of 'libxslt-dev'
  libxslt1-dev is already the newest version.
  0 upgraded, 0 newly installed, 0 to remove and 146 not upgraded.
  </code></pre>
  
  <p>So what gives?  NokoGiri is needing this package, but the package is already installed!! I can't seem to get past this issue, any help out there?</p>