XML Toolchain on Max OS X: failed to load extern..

In this procedure:


After OSX Step 9, when I run make I get the following:

/bin/sh: (cd xhtml; make default): command not found
xsltproc --nonet --xinclude -o glAccum.xml.tmp opengl-man.xsl …/glAccum.xml
I/O error : Attempt to load network entity http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl
warning: failed to load external entity “http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl
compilation error: file opengl-man.xsl line 5 element import
xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl
make[1]: *** [glAccum.xml] Error 5
make: *** [default] Error 2

Has anyone encountered the above?
Has anyone successfully built the man pages on a mac?

Thanks in advance.

My only additions to the Makefile were:

XSLSS = …/docbook-xsl-1.75.2/
XSLT = xsltproc --nonet