Han-Wen Nienhuys writes:
It was a few weeks ago, so I assume that debian throws away old
versions quickly. I expect that this will break in the near future as
well; can we figure out a mechanism that doesn't rely on Debian source
archives? Or one that takes it from a stable version of ubuntu/debian?
Yes, we could, but then it would not be debian_unstable.py. We may
want to disable downloading of debian-unstable stuff by default
(esp. because we do not build debian anyway) or make a switch to
debian_stable.py.