I was trying to execute the below command from the course:
~$ git submodule update --init --recursive
but it failed. Here are the error messages:
fatal: unable to connect to github.com: github.com[0:220.127.116.11] errno=_connection time out
fatal: clone of ‘git://github.com/Ardupilot/PX4Firmware.git’ into submodule path ‘modules/PX4Firmware’ failed.
How do I correct the errors?