rosdep update报错解决

一 .
报错:

reading in sources list data from /etc/ros/rosdep/sources.list.d
ERROR: error loading sources list: ('The read operation timed out',)

解决方法:
更改源, 源的相关配置在以下文件中
1.sudo gedit /etc/ros/rosdep/sources.list.d
2.添加相关源:

/*清华源：*/
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-updates main restricted universe multiverse  
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-updates main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-security main restricted universe multiverse   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-security main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-backports main restricted universe multiverse   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial-backports main restricted universe multiverse   
deb http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial main universe restricted   
deb-src http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports/ xenial main universe restricted 

/*中科大源*/
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-updates main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-updates main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-security main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-security main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-backports main restricted universe multiverse 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial-backports main restricted universe multiverse 
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial main universe restricted 
deb-src http://mirrors.ustc.edu.cn/ubuntu-ports/ xenial main universe restricted

3.sudo apt-get update

二.
报错:

ERROR: unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml]:
	<urlopen error ('_ssl.c:574: The handshake operation timed out',)> (https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml)

解决方法:
1.百度上搜索域名解析,免费提供域名解析的网站有:
https://tool.chinaz.com/dns
2.在该网站的DNS查询中输入https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml,

3.sudo gedit /etc/hosts,添加如下内容:
185.199.110.133 raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml
保存后退出
4.rosdep update

[注]:关于/etc/hosts的具体含义,可参考以下文章
https://blog.csdn.net/qiushisoftware/article/details/89597368