Your package rubygem-open4 failed to build from source in current rawhide. http://koji.fedoraproject.org/koji/taskinfo?taskID=7002950 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_21_Mass_Rebuild
Created attachment 906287 [details] build.log
Created attachment 906288 [details] root.log
Created attachment 906289 [details] state.log