{"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":"self.set_tainted_by_errors(e);"}]}
            self.set_tainted_by_errors(e);
            let e = self.dcx().span_delayed_bug(pat.span, "`Res::Err` but no error emitted");
            return Err(e);