Looks like some change in RPM 4.20 or redhat-rpm-config caused this: https://koschei.fedoraproject.org/build/18071087
Should be relatively straightforward to parametrize the failing test to work on both Fedora <41 and >=41.
This has been fixed in rust-packaging v26.4.
Metadata Update from @decathorpe: - Issue status updated to: Closed (was: Open)