I have Vagrant (1.7.4) configured with the default configuration from vagrant init
using the latest version of VirtualBox (5.0.16 r105871) on OS X (10.11.4) and the
I've figured out what the issue is - while the /vagrant
directory existed on the machine, the shared folder was not being automatically mounted by VirtualBox, despite the auto-mount feature being set to on in the GUI, and the debug output saying that it had indeed been mounted.
Running sudo mount -t vboxsf vagrant /vagrant
manually solves the issue. I put this line into the prestart script for my upstart job to start my server.