如果ubuntu在更新时遇到 Requires installation of unstrusted packages,"The action would require the installation of packages from not authenticated sources."
可以这么解决:
1. sudo apt-get update
把 NO——PUBKEY 记下来, 如上面画红线的地方
2. sudo apt-key adv --recv-key --keyserver keyserver.ubuntu.com XXXXXXXXX
把记下来的NO——PUBKEY 替换XXXXXXXXX
3. sudo apt-get update 这下就好了