If LOCALBASE != /usr/local, configure fails to detect docbook-xml:

checking for DocBook XML DTD V4.3 in XML catalog... not found
checking for DocBook XSL Stylesheets in XML catalog... not found

Explicitly point to location of xml catalog.

Index: Makefile
===================================================================
--- Makefile	(revision 462220)
+++ Makefile	(working copy)
@@ -43,6 +43,7 @@
 OPTIONS_DEFAULT=MANPAGES
 
 MANPAGES_CONFIGURE_ENABLE=	man
+MANPAGES_CONFIGURE_WITH=	xml-catalog=${LOCALBASE}/share/xml/catalog
 MANPAGES_BUILD_DEPENDS=	docbook-xml>=0:textproc/docbook-xml \
 			docbook-xsl>=0:textproc/docbook-xsl
 MANPAGES_USE=	GNOME=libxslt:build