Your package lxpanel failed to build from source in current rawhide. http://koji.fedoraproject.org/koji/taskinfo?taskID=10112091 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_23_Mass_Rebuild
Created attachment 1047304 [details] build.log
Created attachment 1047305 [details] root.log
Created attachment 1047306 [details] state.log