更新源

因为开发环境版本较低，已经不支持一些库包安装，所以要更新一下源

打开source.list 文档

gedit /etc/apt/source.list 如果没有，使用 gedit /etc/apt/sources.list

将下面的内容替换原来的内容

deb http://old-releases.ubuntu.com/ubuntu/  precise main restricted

deb-src http://old-releases.ubuntu.com/ubuntu/  precise main restricted

deb http://old-releases.ubuntu.com/ubuntu/  precise-updates main restricted

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-updates main restricted

deb http://old-releases.ubuntu.com/ubuntu/  precise universe

deb-src http://old-releases.ubuntu.com/ubuntu/  precise universe

deb http://old-releases.ubuntu.com/ubuntu/  precise-updates universe

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-updates universe

deb http://old-releases.ubuntu.com/ubuntu/  precise multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/  precise multiverse

deb http://old-releases.ubuntu.com/ubuntu/  precise-updates multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-updates multiverse

deb http://old-releases.ubuntu.com/ubuntu/  precise-backports main restricted universe multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-backports main restricted universe multiverse

deb http://old-releases.ubuntu.com/ubuntu/  precise-security main restricted

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-security main restricted

deb http://old-releases.ubuntu.com/ubuntu/  precise-security universe

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-security universe

deb http://old-releases.ubuntu.com/ubuntu/  precise-security multiverse

deb-src http://old-releases.ubuntu.com/ubuntu/  precise-security multiverse

deb http://old-releases.ubuntu.com/ubuntu/  precise main

deb-src http://old-releases.ubuntu.com/ubuntu/  precise main

保存退出

sudo apt-get update             //更新源