datadryad/vagrant-dryad — pull request #28 by ryscher (2014-10-21 18:47:49+00:00)
Title: Prevent the VM from filling with useless backups

With each build, remove the previous backup. The build will backup the
current installation, so one backup is always retained.

If the earlier (and mostly useless) backups are not removed, the VM
will eventually run out of disk space.