MarsSeed [1] filed a deletion request for dbus-test-runner-bzr [2]:

Proposal to delete this VCS pkg from 2018.

Upstream not developed since 2019. [a]

As per my checking, the latest main Bazaar branch has the exact same
application code as the one in the last release tarball for v19.04.0.

There seems to be an actively maintained stable package for that
version on AUR. [b]

There were dependency changes in the latter PKGBUILD's v19.04.0
update. So this VCS pkg is now out of alignment with upstream, and is
likely to fail during build in a clean chroot.

But instead of fixing and testing this, I think it is better to
delete, and leave only the functionally equivalent stable package.

[a]: https://launchpad.net/dbus-test-runner
[b]: https://aur.archlinux.org/packages/dbus-test-runner

[1] https://aur.archlinux.org/account/MarsSeed/
[2] https://aur.archlinux.org/pkgbase/dbus-test-runner-bzr/