This kind of problem occurs when we are in Ububtu, which means E: Unable to locate the package problem
The reason for this is that the software source has not been updated, and the updated command is sudo apt-get update
But the source that comes with it is many and old, we can change the source
(1) Enter the directory where the source file is located
cd /etc/apt/(2) Backup source files
sudo cp sources.list sources.list.old(3) Modify the source file inside, use the gedit text editor here, because it can be deleted by ctrl+a
sudo gedit sources.list (4) Delete all the files in it and replace them with the following Aliyuan Alibaba open source ubuntu image , here we take 16.04 as an example
deb http://mirrors.aliyun.com/ubuntu/ xenial main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial main
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb http://mirrors.aliyun.com/ubuntu/ xenial universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main
deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security universe
(5) Update software sources and software
sudo apt-get update
sudo apt-get upgrade