我有如下Rust代码

        let mut str = String::new();
        std::fs::File::open(".last_update.timestamp")
            .unwrap()
            .read_to_string(&mut str)
            .unwrap();
        str.split_whitespace().collect::<Vec<&str>>()[0].parse::<u128>().unwrap()

高亮

.lastupdate.timestamp的内容为

1632558748163255875916325587701632558774163255878416325587861632558787163255878716325587871632558788163255878816325588841632558914

异常为

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ParseIntError { kind: PosOverflow }', src/update.rs:250:74

求slu