Your package rubygem-rails_warden failed to build from source in current rawhide. http://koji.fedoraproject.org/koji/taskinfo?taskID=5771343 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_20_Mass_Rebuild
It failed due to broken Rails. Builds just fine now. Koji: http://koji.fedoraproject.org/koji/taskinfo?taskID=5814022