So after talking about it for a while we finally decided to get netflix and stop buying DVDs.
For a while I have been writing most of my documents in a combination of Org-Mode and Latex and keeping the folders under Git version control.
While preparing some lecture notes in Org mode to be exported using Beamer, this error message confused me today and prevented the pdf being built.
Really easy, quick to make and can be prepared ahead of time.
git branch -m old-branch-name new-branch-name