[Pkg-freeipa-devel] Bug#998575: bind-dyndb-ldap: FTBFS: build-dependency not installable: bind9-libs (= 1:9.16.21-1)

[peter green]

 >  bind9-dev : Depends: bind9-libs (= 1:9.16.21-1) but it is not going to be installed

It looks like bind8 no longer builds the bind9-dev package. It's still present in
unstable as a cruft package but is uninstallable due to version constraints, it's
completely gone from testing.

Bind maintainers: was this a deliberate change? (I can't seem to find any mention of it
in the changelog) and if so what should reverse-dependencies do?