这个输出apt update
看上去还好吗?
$ sudo apt update
Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:2 http://dl.google.com/linux/chrome/deb stable Release
Hit:4 http://ppa.launchpad.net/fingerprint/fingerprint-gui/ubuntu trusty InRelease
Hit:5 http://archive.ubuntu.com/ubuntu xenial InRelease
Hit:6 http://ppa.launchpad.net/js-reynaud/kicad-4/ubuntu trusty InRelease
Hit:7 http://ppa.launchpad.net/stebbins/handbrake-releases/ubuntu trusty InRelease
Ign:8 http://ppa.launchpad.net/stebbins/handbrake-snapshots/ubuntu trusty InRelease
Hit:9 http://ppa.launchpad.net/webupd8team/sublime-text-3/ubuntu trusty InRelease
Hit:10 http://ppa.launchpad.net/stebbins/handbrake-snapshots/ubuntu trusty Release
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
60C58A7169778E6FB8771ADB0816950D8 uses weak digest algorithm (SHA1)