Ubuntu出现无法定位软件包，更换源

在修改source.list前，最好先备份一份

sudo cp /etc/apt/sources.list /etc/apt/sources.list.old

执行命令打开sources.list文件

sudo vim /etc/apt/sources.list

添加阿里云源

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse

更新

sudo apt-get update

Ubuntu出现无法定位软件包，更换源

原文：https://www.cnblogs.com/jiqing9006/p/12582613.html