跑步时
sudo apt update
我在 ubuntu 16.04 终端上得到了这些输出
Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease
Ign:2 http://extras.ubuntu.com/ubuntu precise InRelease
Hit:3 http://ppa.launchpad.net/damien-moore/codeblocks-stable/ubuntu xenial InRelease
Hit:4 http://dl.google.com/linux/chrome/deb stable Release
Ign:5 http://archive.canonical.com/ubuntu precise InRelease
Hit:7 http://ppa.launchpad.net/git-core/ppa/ubuntu xenial InRelease
Ign:8 http://us.archive.ubuntu.com/ubuntu precise InRelease
Hit:9 http://archive.canonical.com/ubuntu precise Release
Get:6 http://extras.ubuntu.com/ubuntu precise Release [11.9 kB]
Hit:10 http://ppa.launchpad.net/nilarimogard/webupd8/ubuntu xenial InRelease
Hit:12 http://us.archive.ubuntu.com/ubuntu precise-security InRelease
Hit:13 http://ppa.launchpad.net/ubuntu-desktop/ubuntu-make/ubuntu xenial InRelease
Get:14 http://extras.ubuntu.com/ubuntu precise Release.gpg [72 B]
Hit:16 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease
Get:17 http://us.archive.ubuntu.com/ubuntu precise-updates InRelease [55.7 kB]
Hit:18 http://ppa.launchpad.net/webupd8team/sublime-text-3/ubuntu xenial InRelease
Hit:19 http://apt.postgresql.org/pub/repos/apt xenial-pgdg InRelease
Ign:14 http://extras.ubuntu.com/ubuntu precise Release.gpg
Hit:20 http://us.archive.ubuntu.com/ubuntu precise-backports InRelease
Hit:21 http://us.archive.ubuntu.com/ubuntu precise Release
Hit:23 https://deb.nodesource.com/node_7.x xenial InRelease
Reading package lists... Done
W: http://archive.canonical.com/ubuntu/dists/precise/Release.gpg: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-security/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: GPG error: http://extras.ubuntu.com/ubuntu precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192
E: The repository 'http://extras.ubuntu.com/ubuntu precise Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-updates/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-backports/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: http://us.archive.ubuntu.com/ubuntu/dists/precise/Release.gpg: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
有人能帮我找出解决这些错误的办法吗？