If Doxyfile contains HTML_TIMESTAMP = YES, Doxygen will add a timestamp to its generated (HTML) documentation.
It seems Doxygen has no way to turn it off for man-pages, see ReproducibleBuilds/TimestampsInManpagesGeneratedByDoxygen.
A good amount of potentially affected packages can be found using codesearch.
Detection
Solution
A patch has been sent to Doxygen upstream which honours the implementation of the new environment variable SOURCE_DATE_EPOCH. This was proposed as a way to produce deterministic timestamps [1].
Upstream bug:https://bugzilla.gnome.org/show_bug.cgi?id=751984
This solution avoids having to carry a patch against upstream (only if doxygen is called in debian/rules):
override_dh_auto_build-indep: { cat Doxyfile && echo "HTML_TIMESTAMP=NO"; } | doxygen -
Otherwise, patch upstream
either by setting HTML_TIMESTAMP = NO in Doxyfile
- or by removing the $timestamp placeholder in the html file referenced by the configuration variable HTML_FOOTER.
Example patch 1, Example patch 2
[1] https://wiki.debian.org/ReproducibleBuilds/TimestampsProposal