We're in the progress of switching rpm's database from BerkeleyDB to the new
"ndb" database. Libzypp can already deal with that change, but the
CheckRPMDBforExistency function in update_proposal.rb only checks for
"Packages" and "packages.rpm". The ndb database is named "Packages.db", though.

You can either:

- add "Packages.db" to the list

- only check the existence of the "/var/lib/rpm" directory (this is what
Michael Andres suggests)

- use some to-be-added function in the bindings to ask libzypp if the database
exists