Many BTS pages contain the text "The current version can be obtained
from https://bugs.debian.org/debbugs-source/.", but that link doesn't
actually work; instead of going to the source, it attempts to look up
the bugs of a package by that name (which fails, as no such package exists).

I am not sure where it should point to:
https://sources.debian.org/src/debbugs/ is currently version 2.6.2,
https://salsa.debian.org/debbugs-team/debbugs is version 3.0.0~alpha.1
(on master) and 2.6.1 (on release_2.6), and I don't know exactly what
version bugs.debian.org is.