If you have trouble getting XML::LibXML and/or XML::LibXSLT to work on
OS X, try installing these (old) versions:
http://xmlsoft.org/sources/old/libxml2-2.6.8.tar.gz
http://xmlsoft.org/sources/old/libxslt-1.1.5.tar.gz
(You'll probably get errors in "make test".)