本质就是PPA的问题，解决了PPA其他就迎刃而解。

sudo su -

echo "deb http://ppa.launchpad.net/ondrej/php/ubuntu xenial main" | tee -a /etc/apt/sources.list

echo "deb-src http://ppa.launchpad.net/ondrej/php/ubuntu xenial main" | tee -a /etc/apt/sources.list

apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E5267A6C

apt-get update exit