Your package NLopt failed to build from source in current rawhide. http://koji.fedoraproject.org/koji/taskinfo?taskID=10075798 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_23_Mass_Rebuild
Created attachment 1046356 [details] build.log
Created attachment 1046357 [details] root.log
Created attachment 1046358 [details] state.log
Build for fc23 succeeded [1] after a small patch. [1] https://koji.fedoraproject.org/koji/buildinfo?buildID=667250