{"ast_node_type":"other","tokens":[{"end":78,"kind":"keyword","start":0,"text":"err.span_label(span,"}]}
                err.span_label(span, "type aliases cannot be used as traits");
            (Res::Def(DefKind::TyAlias, def_id), PathSource::Trait(_)) => {
                if self.r.tcx.sess.is_nightly_build() {