问题描述

使用 sudo apt get-install 出现 E: Failed to fetch问题。

更换镜像源

错误原因：绝大多数情况下，ROS更新的下载源都是正常的，所以出现这个问题，应该是自己系统一些配置设置问题。

既然网络出现问题，我们更换下载源：

使用gedit或vi/vim打开配置文件:

• sudo gedit /etc/apt/sources.list

或者

• sudo vim /etc/apt/sources.list

替换里面全部内容

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

配置DNS网关

• Terminal下输入命令

sudo gedit /etc/resolv.conf

或者

sudo vi /etc/resolv.conf

• 在resolv.conf里面添加阿里DNS

nameserver 223.5.5.5
nameserver 223.6.6.6

• 然后生效配置文件（刷新列表）

sudo apt-get update

注意：一定要执行刷新