If your project uses git submodules and the clone step hangs, ensure submodules use relative or SSH paths to resolve the issue.
Symptoms
My project is configured to use git submodules, and the clone step is hanging.
Resolution
If your project is configured to use git submodules and the clone step is hanging, verify that your submodules are configured to use either the relative path or the SSH path to the submodule.
More Information
This Stack Overflow post has an excellent example of using relative paths.
https://stackoverflow.com/a/44630028