As I mentioned in a previous mail to debian-release the dependency tracking in auto-removals seems to be buggy, this has resulted in britney trying and failing to remove rust-rand. This in turn blocks any attempt to migrate the new (and fixed) rust-rand.
I am bumping this bug report to get the broken auto-removals out of the way so that britney attempts to migrate rust-rand to testing (and either it succeeds, in which case great, or we at least find out what is blocking it).