Earlier quoted context omitted.
you, and they, were doing it wrong. The point of vagrant is that you type 'vagrant up' and you have a working environment. All of my projects use vagrant to ensure compatibility. You can 'git clone' and 'vagrant up' and have a working environment as soon as the provisioning task completes.
Thanks for the help. I trust that the people who provided whatever configuration it used knew what they were doing, but it was still incredibly flaky.
You should never trust that people know what they are doing in this industry.