One should be able to import changes which do not build locally, as an exception.
In order to make distributed development more robust, such changes should be received cleanly, without changing the UUIDs. Then the importer would fix the build in a subsequent change, and publish the corrective change. This would make everyone's change history consistent.
Currently, one has to change the build_command in order to import such a change, which is not clean. (It modifies the change UUID, which confuses aedist.)
I attach a simple changeset which allows for this, with minimal disruption.