This actually is a warning, not an error, in that the installation still proceeds. The issue is a known one, with a workaround at present being to use a default SAX parser other than XML::SAX::PurePerl. You can do this by:

• installing, for example, XML-SAX-ExpatXS;
• issuing the following command to register it (all on one line):

  C:\>perl -MXML::SAX -e "XML::SAX->add_parser(q(XML::SAX::ExpatXS))->sa
  +ve_parsers()"
  [download]