{"ast_node_type":"variable","tokens":[{"end":42,"kind":"keyword","start":0,"text":"let"}]}
    let rustc_version = String::from_utf8(
    let toolchain_arg = format!("+{toolchain}");
        run_command_with_env(&[&args.config_info.rustc_command[0], &"-V"], cwd, Some(env))?.stdout,