I submitted the patches through Salsa: https://salsa.debian.org/games-team/0ad/-/merge_requests/6 It builds and then runs nicely on my up-to-date Debian unstable.
I sneaked in a fix to ensure DEB_BUILD_OPTIONS=parallel=${n} is honoured, as I needed it to ensure the package could be built on a low-RAM system. If you would rather have these two changes it two distincts merge requests, I can do that (they are already in distinct commits). And if you would like me to upload a source package to mentors, I can do that too.