Description:

“docbook2man --sgml” fails to create man page from sgml file. After initial investigation, it appears “docbook2man --sgml” is using in the process “sgml2xml-isoent” (simple wrapper script), which in turn depends on a tool “sgml2xml”. Closer look at “sgml2xml-isoent”, shows at the very end of the file:

# The purpose of the following slew of redirections
# is to get the error messages in the right place
# and to return sx/osx exit status.
# (the sed and grep are unlikely to fail)

# Prefer sx (sgml2xml) over osx because it is faster

if test -x ""; then
exec 3>&1 4>&2;
status=`((("" -xid -xlower "$@"; echo $? >&5) | sed -e "$sed_script") 2>&1 1>&3 | grep -v "$sx_whining" 1>&4) 5>&1`;
exit $status;

elif test -x ""; then
exec 3>&1 4>&2;
status=`(("" -xid -xlower -xsdata-as-pis "$@"; echo $? >&5) | sed -e "$sed_script") 5>&1 2>&4 1>&3`;
exit $status;
else
echo "$0: cannot find sx(sgml2xml) or osx to convert SGML to XML. Cannot continue." 2>&1
exit 255;
fi

Then the “cannot find sx(sgml2xml)…” part appears during the attempted use of “docbook2man --sgml” as follows:

bodzio@gizmo ~/scratchpad/imdb-tools/src/imdb-tools-0.8 : docbook2man --sgml imdb-link.sgml
-:1: parser error : Start tag expected, '<' not found
/usr/bin/sgml2xml-isoent: cannot find sx(sgml2xml) or osx to convert SGML to XML
^
unable to parse -
Unable to recognise encoding of this document at /usr/share/perl5/vendor_perl/XML/SAX/PurePerl/EncodingDetect.pm line 100.
Document requires an element [Ln: 1, Col: 0]

Apparently “docbook2x” misses sgml to xml converter.

Additional info:
package version: docbook2x-0.8.8-10

Steps to reproduce:
Use “docbook2man --sgml” on any docbook sgml file.