Hi Lucas (is it you, or a bot?), thanks for the new bug report about doxygen 1.8.20-4 FTBFS on arm64: https://bugs.debian.org/976495
I had noticed this issue yesterday and worked around it with 1.8.20-5 but the real fix will come with 1.8.20-6, thanks to a tip from Norbert Preining: https://bugs.debian.org/976405#10 It would be interesting to know when you last run the archive rebuild on arm64 or amd64, because it's not clear since when this error happens. Paolo