title: Libxml-ruby error on Rails app startup -- uninitialized constant LibXML::XML::Error::I18N
body: <p>I just updated to Rails 3.2.12 and Bundler also updated libxml-ruby from 2.4.0 to 2.5.0. When I restart my production server (nginx), or try to open a console, I get:</p>
  
  <pre><code>/home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:10:in `const_get': uninitialized constant LibXML::XML::Error::I18N (NameError)
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:10:in `block (2 levels) in &lt;class:Error&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:8:in `each'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:8:in `block in &lt;class:Error&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:7:in `tap'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:7:in `&lt;class:Error&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:5:in `&lt;module:XML&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:4:in `&lt;module:LibXML&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml/error.rb:3:in `&lt;top (required)&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/libxml.rb:11:in `&lt;top (required)&gt;'
      from /home/cceom/webapps/rails2/gems/gems/libxml-ruby-2.5.0/lib/xml.rb:13:in `&lt;top (required)&gt;'
  </code></pre>
  
  <p>I'm not having the same issue on my dev box.</p>
  
  <p>All I can figure is that some how the 2.5.0 gem is still referencing the old 2.4.0 compiled libraries and that particular constant is not defined in them. But no idea how this would happen nor how to rectify it. Nor whether this is even correct.</p>
  
  <p>Any thoughts would be welcome.</p>