Confusing error when Git is missing

[endymion]

This is an error that I have encountered a lot while setting up development VMs with Vagrant to use a technology stack that includes gitlab-grit:

http://f.cl.ly/items/1G3H0F0X0P0S2P091W04/vagrantvaultwikivagrant$%20rake%20.txt

That error is really confusing. What it really means is, "Git is not installed."

I have learned my way around this, but it could save a lot of grief for people in the future if there were a clearer error message when Git is missing.