gtk+ is using %{?_isa} in BuildRequires which is prohibited by Packaging Guidelines: https://fedoraproject.org/wiki/Packaging:Guidelines#BuildRequires_and_.25.7B_isa.7D. Please fix it ASAP.
%changelog * Wed Feb 14 2018 Rex Dieter <rdieter> - 1:1.2.10-87 - drop using arch-dependent BuildRequires (#1545186) - -devel: drop explicit Requires: pkgconfig