At the top of the script, the line from github_backup import __version__ gets the script's version number to use if the script is called with the -v or --version flags. The problem is that if the script hasn't been installed via pip (for example I cloned the repo directly to my backup server), the script will fail due to an import exception. Also presumably it will always use the version number from pip even if running a modified version from git or a fork or something.

PR incoming with a fix :)