Installation fails: libxml2 is missing

[reitzig]

When I try to sudo gem install link-checker, I get this:

Fetching: nokogiri-1.5.11.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing link-checker:
    ERROR: Failed to build gem native extension.

    /usr/bin/ruby2.0 extconf.rb
checking for libxml/parser.h... no
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libxml2 is missing.

The thing is, libxml2 is installed on my system. Also, I have nokogiri (1.6.6.2) already there. I'm using Ruby 2.0.0.

I think this may be a regression, fixable by updating the dependencies to allow the latest versions?