{"ast_node_type":"variable","tokens":[{"end":76,"kind":"keyword","start":0,"text":"let"}]}
            let guar = cx.dcx().emit_err(errors::EnvTakesArgs { span: sp });
        Ok(exprs) if exprs.is_empty() || exprs.len() > 2 => {
            return ExpandResult::Ready(DummyResult::any(sp, guar));