The webkitgtk3 package will be removed from rawhide after Fedora 26 is branched due to the high number of unfixed security vulnerabilities. You must remove this dependency or your package will not be present in Fedora 27. Please refer to [1] for a FAQ on this matter and be advised that for some packages this may require a substantial amount of work. [1] https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/AKVB363GFCHHJ5MTHGVYHYT6NLLTF5VM/
This bug appears to have been reported against 'rawhide' during the Fedora 26 development cycle. Changing version to '26'.