{"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"let"}]}
            let n = self.flags.treat_err_as_bug.map(|c| c.get()).unwrap();
        if self.treat_err_as_bug() {
            assert_eq!(n, self.err_guars.len() + self.lint_err_guars.len());