Ubuntu换源

前言：按照网上换源的方法出现：Unable to correct problems, you have held broken packages

一、查看系统Codename：

lsb_release -a

或者

cat /etc/apt/sources.list

二、确认阿里源支持：登陆以下网页：http://mirrors.aliyun.com/ubuntu/dists/

三、更换源

sudo cp /etc/apt/sources.list /etc/apt/sources.list_bak
sudo vi /etc/apt/sources.list

以下内容：注意，每一行的bionic应该用第一步查看得到的Codename来代替

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

四、更新

更新源

sudo apt-get update

修复损坏的包，重新安装正确版本

sudo apt-get -f install

更新软件

 sudo apt-get upgrade