Snapshot appears to have been created more than one day into the future!
Raspberry PI 4b上安装freebsd13.2 aarch系统后，使用ssh链接，输入portsnap fetch extract命令，提示：
Snapshot appears to have been created more than one day into the future!
(Is the system clock correct?)
Cowardly refusing to proceed any further.
原来是安装时系统时间不正确 执行代码:
ntpdate pool.ntp.org
然后再执行portsnap fetch即可。
来源：https://blog.haohtml.com/archives/7188
更多portsnap命令：
https://www.cyberciti.biz/faq/install-ports-in-freebsd/