Your package lightdm-gtk failed to build from source in current F28. https://koji.fedoraproject.org/koji/taskinfo?taskID=24877933 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild
Already rebuild at Tue, 06 Mar 2018. https://koji.fedoraproject.org/koji/buildinfo?buildID=1054267 Btw. why you're filing out reports about obsolete package versions?