1.問題描述：
***@***:~$ rosdepupdate
readingin sources list data from /etc/ros/rosdep/sources.list.d
ERROR:unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml]:
<urlopen error ('_ssl.c:574: The handshake operation timedout',)> (https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml)
ERROR:unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml]:
<urlopen error timed out> (https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml)
ERROR:unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml]:
<urlopen error timed out> (https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml)
ERROR:unable to process source [https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml]:
<urlopen error timed out> (https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml)
Hit https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml
Queryrosdistro index https://raw.githubusercontent.com/ros/rosdistro/master/index.yaml
Adddistro "groovy"
Adddistro "hydro"
ERROR:error loading sources list:
('The read operation timed out',)
2.解決方法：
***@***:~$ sudo rm/etc/ros/rosdep/sources.list.d/20-default.list
lxd@lxd-K43SJ:~$sudo rosdep init
ERROR:cannot download default sources list from:
https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/sources.list.d/20-default.list
Websitemay be down.
***@***:~$ sudo apt-getupdate
命中:1 https://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial InRelease
命中:2 https://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-updates InRelease
命中:3 https://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-backports InRelease
命中:4 https://mirrors.tuna.tsinghua.edu.cn/ubuntu xenial-security InRelease
命中:5 http://packages.ros.org/ros/ubuntu xenial InRelease
正在讀取軟件包列表... 完成
***@***:~$ sudo rosdep init
Wrote/etc/ros/rosdep/sources.list.d/20-default.list
Recommended:please run
rosdep update
***@***:~$ rosdep update
readingin sources list data from /etc/ros/rosdep/sources.list.d
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/osx-homebrew.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/base.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/python.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/ruby.yaml
Hit https://raw.githubusercontent.com/ros/rosdistro/master/releases/fuerte.yaml
Queryrosdistro index https://raw.githubusercontent.com/ros/rosdistro/master/index.yaml
Adddistro "groovy"
Adddistro "hydro"
Adddistro "indigo"
Adddistro "jade"
Adddistro "kinetic"
Adddistro "lunar"
Adddistro "melodic"
updatedcache in /home/lxd/.ros/rosdep/sources.cache