ERROR: cannot download default sources list from

[zhangbowei]

INFO:Docker Client: ---> Using cache
INFO:Docker Client: ---> 51b24e7a5475
INFO:Docker Client:Step 6/10 : RUN rosdep init
INFO:Docker Client: ---> Running in 827623083c95
INFO:Docker Client: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.
ERROR:Docker Client:Error building Docker image. The follow error was caught:
The command '/bin/sh -c rosdep init' returned a non-zero code: 4
NoneType: None
Traceback (most recent call last):
File "/usr/local/lib/python3.8/runpy.py", line 192, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/usr/local/lib/python3.8/runpy.py", line 85, in _run_code
exec(code, run_globals)

[christophebedard]

You might need to set up a proxy to be able to access the GitHub website.