title: Problem installing nokogiri - "Package libxslt-dev is a virtual package"
body: <p>I'm trying to install the nokogiri gem in ubuntu.  I've followed the instructions on this page: <code>http://nokogiri.org/tutorials/installing_nokogiri.html</code></p>
  
  <p>I've done the first steps ok:</p>
  
  <pre><code># ruby developer packages
  sudo apt-get install ruby1.8-dev ruby1.8 ri1.8 rdoc1.8 irb1.8
  sudo apt-get install libreadline-ruby1.8 libruby1.8 libopenssl-ruby
  </code></pre>
  
  <p>But when i try to do the next step, <code>sudo apt-get install libxslt-dev</code>, i get this error:</p>
  
  <pre><code>Package libxslt-dev is a virtual package provided by:
  libxslt1-dev 1.1.24-2ubuntu2
  You should explicitly select one to install.
  E: Package libxslt-dev has no installation candidate
  </code></pre>
  
  <p>I've no idea what this means, or how to select one (one of what?).  Can anyone help?  </p>