Thanks for inadvertently solving a packaging error I was baffled by! I don’t know if this affects the priority/relevance of this bug, but FYI I was midway through packaging an updated version of Rumur and (guided by this bug report) removed my debian/rumur.manpages entirely so this is no longer a blocker for me. Mentors upload link for reference:
https://mentors.debian.net/debian/pool/main/r/rumur/rumur_2019.10.27-1.dsc
