ubuntu20.04 清華源 update 報證書錯誤

換成清華源後，

https://mirror.tuna.tsinghua.edu.cn/help/ubuntu/

 

sudo  apt update

報證書錯誤，

Certificate verification failed: The certificate is NOT trusted. The .....

將所有https改爲http

然後執行：

audo apt install ca-certificates

然後再改回來https，再update即可。