docbook2X converts DocBook to man pages in two steps:
Man-XML is simpler than DocBook and closer to the man page format; it is intended to make the stylesheets' job easier.
The stylesheet for this purpose is in xslt/man/docbook.xsl. For portability, it should always be referred to by the following URI:
http://docbook2x.sourceforge.net/latest/xslt/man/docbook.xsl
Run this stylesheet with db2x_xsltproc.
db2x_manxml.
The docbook2man (see Wrapper scripts manual page) command does both steps automatically,
but if any problems occur, you can see the errors more clearly
if you do each step separately:
$ db2x_xsltproc -s man mydoc.xml -o mydoc.mxml
$ db2x_manxml mydoc.mxml