perl Makefile.PL LIBS='-L/usr/local/lib -lxml2 -lz -lpthread -liconv -lm' INC='-I/usr/local/include/libxml2'
Set up build environment without MacOSX10.4u SDK (will build native binaries)
enable native perl UTF8
looking for -lxml2... no
looking for -llibxml2... no
libxml2 not found
Try setting LIBS and INC values on the command line
Or get libxml2 from 
  http://xmlsoft.org/
If you install via RPMs, make sure you also install the -devel
RPMs, as this is where the headers (.h files) are.