Cylindrical ROV for polar research

@EliotBR, I was following this page in order to setup the ArduSub repository from github. This seemed to work as it should, but then I found this post. Here, you mention that it’s preferrable to clone the repository from your own github and not the official ardupilot project. I went ahead and made a fork from the ardupilot/ardupilot project unto my own github and cloned from there. Now I get the following error:

$ git checkout ArduSub-stable
error: pathspec ‘ArduSub-stable’ did not match any file(s) known to git

Any ideas as to what may be causing this?
I’ve since tried removing the repository and cloning from ardupilot/ardupilot again and I am then able to checkout with no errors:

$ git checkout ArduSub-stable -b new-branch
Updating files: 100% (5123/5123), done.
Switched to a new branch ‘new-branch’