Last Updated: 2021-05-15
My Project S readme had the line
vagrant box add laravel/homestead --provider virtualbox
This failed on X's machine. In reality, this should only be run when setting up Vagrant. Otherwise, it's unneeded and -- in fact -- causes issues when you attempt to run it again.
In order to write a good README, attempt to start the project from scratch using those instructions. Some of them will turn out to be problematic to run twice.