Comigrate
=========

* on "break" architectures, we need to remove binary packages without
  corresponding source packages from the Heidi output
  (or do we have the right semantics for these architectures?)
  ===> we should just not check co-installability on break_arch ???
       (but not true for smooth upgrade...)

* Issue with --equivocal (not the same choices made in both cases...)
  We should probably start by checking just installability, and then
  refine with co-installability.

  Fatal error: exception Assert_failure("transition.ml", 2517, 2)
  Called from file "transition.ml", line 2538, characters 4-70
  Called from file "transition.ml", line 2706, characters 2-6
