Your package python-rdflib failed to build from source in current F28. https://koji.fedoraproject.org/koji/taskinfo?taskID=24880849 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild
Logs are missing in Koji so it's a bit hard to see what went wrong... It builds locally for me in mock, although with a large number of test failures that are then suppressed...
Hmm okay. The failed build was: python-rdflib-4.2.1-4.fc28 Then the test failures were suppressed: https://src.fedoraproject.org/rpms/python-rdflib/c/7fe1b1a7d492a1c48e30eb75d9a8d918f0f809dc and there was a successful build: python-rdflib-4.2.1-5.fc28 but that build is tagged f29, not f28, in spite of its dist tag. 🤔 Not sure how that happened.
But anyway, it seems we still have python-rdflib-4.2.1-2.fc26 in Fedora 28 right now, which is the same code. And we have successful builds on the f28 branch (in case it needs any fixes during Fedora 28 release cycle). So I don't think there is anything else we need to do here.