Your package rubygem-ffi failed to build from source in current rawhide. http://koji.fedoraproject.org/koji/taskinfo?taskID=5769377 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_20_Mass_Rebuild
This bug appears to have been reported against 'rawhide' during the Fedora 20 development cycle. Changing version to '20'. More information and reason for this action is here: https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora20
rubygem-ffi-1.4.0-4 is now built in rawhide: http://koji.fedoraproject.org/koji/buildinfo?buildID=514823