It seems to me the biggest surprise comes from not getting a repo that is what I'm asking it to be. Without this changeset, asking `vcsrepo` to set a repo to a specific revision is nondeterministic. If some external entity added files to the repo and I did not know about them (i.e. I did not add them to my `.gitignore`), it may mess up my procedure without me ever knowing.

(That was the reason for this change set, actually. Hard to find when you rely on Puppet to set up the prod all for you.)