Comparison of branches on CI

[Andreas Enge]

Hello,

Leo mentioned some time ago that cuirass was missing useful functionality
from hydra, and I wonder if I have not come across one. How about comparison
of different branches and/or evaluations? I did not see how to do it, but
maybe I just overlooked something.

For instance for the core-update merge (but also later feature branches),
it would be useful to distinguish problems in core-updates from those
already present in master; otherwise said, packages that we would lose
by making the merge. If core-updates is not 100% okay, but does not present
(important) regressions with respect to master, we may as well merge it and
sort out remaining problems in master. Is there a way of making this
comparison with our current tools?

Andreas