Your package curl failed to build from source in current rawhide. https://koji.fedoraproject.org/koji/taskinfo?taskID=17712935 For details on mass rebuild see https://fedoraproject.org/wiki/Fedora_26_Mass_Rebuild
Created attachment 1251702 [details] build.log
Created attachment 1251703 [details] root.log
Created attachment 1251704 [details] state.log
I am not sure whether it is related or not ... but I cannot further debug this issue until bug #1423434 is resolved.
kdudka's curl-7.53.0-1.fc26 completed http://koji.fedoraproject.org/koji/buildinfo?buildID=860936
valgrind temporarily disabled on x86 via: http://pkgs.fedoraproject.org/cgit/rpms/curl.git/commit/?id=efea9223