mitchellh/vagrant — pull request #2414 by Schpidi (2013-10-23 21:05:40+00:00)
Title: Automatically enable symlinks on vboxsf for VirtualBox 4.1

See #713 and 387692f9c8fa4031050646e2773b3d2d9b2c994e

Note, VirtualBox 4.1 is still used for example in Ubuntu 12.04 LTS.