sudo apt update && sudo apt dist-upgrade
Hit:1 http://ports.ubuntu.com/ubuntu-ports xenial InRelease
Hit:2 http://ports.ubuntu.com/ubuntu-ports xenial-security InRelease
Hit:3 http://ports.ubuntu.com/ubuntu-ports xenial-updates InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
7 packages can be upgraded. Run 'apt list --upgradable' to see them.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done'
The following packages have been kept back:
xorg xserver-xorg xserver-xorg-core xserver-xorg-input-all
xserver-xorg-input-evdev xserver-xorg-input-void xserver-xorg-video-dummy
0 upgraded, 0 newly installed, 0 to remove and 7 not upgraded
当我打开时update-manager出现以下内容：
You don't have the required privileges to perform this action.
我按下“确定”，出现如下画面：
the software on this computer is up to date.
However, Ubuntu 18.04.2 LTS is now available (you have 16.04)
我按下“升级”。什么也没发生。
sudo do-release-upgrade
Checking for a new Ubuntu release Please install all available updates for your release before upgrading.
lsb-release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04.6 LTS
Release: 16.04
Codename: xenial
cat /etc/apt/sources.list
deb http://ports.ubuntu.com/ubuntu-ports/ xenial main universe restricted multiverse
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse main restricted universe
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates multiverse main restricted universe
sudo nano /etc/apt/sources.list
deb http://ports.ubuntu.com/ubuntu-ports/ xenial main universe restricted multiverse
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-security multiverse main restricted universe
deb http://ports.ubuntu.com/ubuntu-ports/ xenial-updates multiverse main restricted universe
答案1
通过编辑“sources.list”解决问题
sudo nano /etc/apt/sources.list
我只是修改了 sources.listnano /etc/apt/sources.list并删除了通过运行发现的停止升级的行apt list --upgradable