but if this situation is true and expected,
forcing it is fine.
+git-debrebase will try to look for the dgit archive view
+of the most recent release,
+and if it finds it will make a pseduomerge so that
+your new git-debrebase view is appropriately fast forward.
+
The result is a well-formed git-debrebase interchange branch.
The result is also fast-forward from the gbp branch.