In libzypp-17.14.0 and upstream as of today, libzypp assumes that rpmdb has a file named Packages in several places in zypp/target/rpm/RpmDb.cc.
As of rpm >= 4.13, this is not a valid assumption.
Submitted issue upstream. There's some background work already started as SUSE seems to be looking to replace bdb with ndb: https://github.com/openSUSE/post-build-checks/pull/29
FEDORA-2020-e9594e8e99 has been submitted as an update to Fedora 30. https://bodhi.fedoraproject.org/updates/FEDORA-2020-e9594e8e99
FEDORA-2020-3e8b579933 has been submitted as an update to Fedora 31. https://bodhi.fedoraproject.org/updates/FEDORA-2020-3e8b579933
libzypp-17.22.0-1.fc30, zypper-1.14.33-1.fc30 has been pushed to the Fedora 30 stable repository. If problems still persist, please make note of it in this bug report.
libzypp-17.22.0-1.fc31, zypper-1.14.33-1.fc31 has been pushed to the Fedora 31 stable repository. If problems still persist, please make note of it in this bug report.