What would have helped me was if these instructions said something like, “Hey dummy! Don’t run the git clone command from the shell. Just add the command to the app.yml file per the example, make sure the indents are correct, save it, and then run the rebuild command.”
These instructions could also be clearer when -E -u are necessary and when they are not.
I did some other dumb things to before I succeeded. When I look at the instructions now, they make nearly perfect sense. But I fell into several pitfalls that I might have avoided if these instructions were written considering noobs like me would be trying to follow them.