Vagrant Shared Directory Hangs on Ubuntu 13.10

The Symptom

Performing any operation on the Vagrant shared directory hangs. E.g. ls /vagrant.

How to Fix It

Detail: What causes this symptom

The problem occurs with the following configuration:

The shared folders hang because of a small bug that was fixed in version 4.3 of VirtualBox (see the bugfix in changeset 48529). Updating VirtualBox on the host machine is easy, you just install the latest version. Unfortunatly the bug wasn’t in the code for the host, but within the Guest Additions source (trunk/src/VBox/Additions/linux/sharedfolders/dirops.c). The version of Guest Additions hard baked into the Ubuntu 13.10 Vagrant box is older than 4.3, so doesn’t have the fix.

The vagrant-vbguest plugin sorts this by checking the version of the Guest Additions on startup, and updating it if neccessary.