I reported this problem for Ubuntu as well: https://bugs.launchpad.net/ubuntu/+source/gtk-doc/+bug/989580
This worked fine in Debian squeeze, but I have now confirmed that the bug exists in Debian wheezy as well. The fix should be to build-depend on some package to make 'dblatex' be available during ./configure run. /Simon PS. If someone needs to work around this problem meanwhile it is fixed properly, they can apply the attached patch.
--- /usr/bin/gtkdoc-mkpdf.orig 2012-03-19 07:36:54.000000000 +0100 +++ /usr/bin/gtkdoc-mkpdf 2012-05-15 23:42:24.526105343 +0200 @@ -87,7 +87,7 @@ fi if $is_xml; then - if test -n ""; then + if test -n "/usr/bin/dblatex"; then # extra options to consider # -I FIG_PATH # -V is useful for debugging @@ -97,15 +97,15 @@ # xsltproc is already called with --xinclude # does not work: --xslt-opts "$path_arg --nonet $@" dblatex_options="-o $module.pdf $imgdirs $document" - #echo "calling: $dblatex_options" + #echo "calling: /usr/bin/dblatex $dblatex_options" if test $verbose = "0"; then - 2>&1 --help | grep >/dev/null "\-\-quiet" + /usr/bin/dblatex 2>&1 --help | grep >/dev/null "\-\-quiet" if test "$?" = "0"; then dblatex_options="--quiet $dblatex_options"; fi; - 2>&1 >/dev/null $dblatex_options | grep -v 'programlisting or screen' + /usr/bin/dblatex 2>&1 >/dev/null $dblatex_options | grep -v 'programlisting or screen' else - { 2>&1 >&3 $dblatex_options | grep -v 'programlisting or screen' >&2; } 3>&1 + { /usr/bin/dblatex 2>&1 >&3 $dblatex_options | grep -v 'programlisting or screen' >&2; } 3>&1 fi else if test -n ""; then