ERROR: cannot download default sources list from: https://raw.githubusercontent.com/ros/rosdistro/master/rosdep/sources.list.d/20-default.list Website may be down.
報錯原因是GitHub的`raw.githubusercontent.com`無法連接
需要解決GitHub的`raw.githubusercontent.com`無法連接問題
通過`IPAddress.com`首頁,輸入`raw.githubusercontent.com`查詢到真實IP地址
修改hosts Ubuntu,
sudo vi /etc/hosts
添加以下內容保存即可
199.232.28.133 raw.githubusercontent.com
轉(http://qjzd.net:3000/topic/5e48cc33dcf06d6a181ffb81)
然後輸入`sudo rosdep init`就可以了