Your package avahi failed to build from source in current F28. https://koji.fedoraproject.org/koji/taskinfo?taskID=24769396 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild
A build was successfull: avahi-0.7-12.fc28 An update was found in bodhi: avahi-0.7-12.fc28 rpm bugfix stable 2018-04-09