Hi,
1) Using this https://fedoraproject.org/wiki/Packaging:Guidelines#Requiring_Base_Package as a base, I suggested (not in any bug) to add %{?_isa} for -libs also in ibus.spec to its maintainer. Following is a part of commit he did. But he also then said this looks unnecessary to him as %{name}%{?_isa} already present.
%package gtk3
-Summary: IBus im module for gtk3
-Group: System Environment/Libraries
-Requires: %{name}%{?_isa} = %{version}-%{release}
-Requires: %{name}-libs = %{version}-%{release}
+Summary: IBus im module for gtk3
+Group: System Environment/Libraries
+Requires: %{name}%{?_isa} = %{version}-%{release}
+Requires: %{name}-libs%{?_isa} = %{version}-%{release}
-- packaging mailing list packaging@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/packaging