I still find very odd that
$ dak rm -Rn python-setuptools-scm
doesn't find anything though. dak is obviously aware of the package...
You missed -b for binary packages:
$ dak rm -Rn -b python-setuptools-scm
Will remove the following packages from unstable:
python-setuptools-scm | 4.1.2-3 | all
Maintainer: Debian Python Modules Team
<python-modules-t...@alioth-lists.debian.net>
------------------- Reason -------------------
----------------------------------------------
Checking reverse dependencies...
No dependency problem found.
A RM bug for manual cruft removal of this arch:all package should fix it ...
Andreas