On Fedora 19, with the following packages: libxml2-2.9.1-1.fc19.i686 rubygem-nokogiri-1.5.9-1.fc19.i686 Any scripts using nokogiri print a warning that nokogiri was built against a different libxml version. A simple reproduction case: $ ruby -rnokogiri -e '' WARNING: Nokogiri was built against LibXML version 2.9.0, but has dynamically loaded 2.9.1 Koji confirms that nokogiri was indeed originally built against libxml2-2.9.0-4.fc19: http://kojipkgs.fedoraproject.org//packages/rubygem-nokogiri/1.5.9/1.fc19/data/logs/i686/root.log My guess is that a simple rebuild for F19 would fix this.
Looks like this is no longer an issue on Fedora 20 (rubygem-nokogiri-1.6.1-1.fc20.1) $ ruby -rnokogiri -e '' is silent.