If you're using Vagrant 1.8+ and VirtualBox 5 you may get the following error when starting the VM:
Vagrant attempted to execute the capability 'configure_networks' on the detect guest OS 'linux', but the guest doesn't support that capability. This capability is required for your configuration of Vagrant. Please either reconfigure Vagrant to avoid this capability or fix the issue by creating the capability.
It's caused by Precise not having an /etc/os-release file which vagrant relies on. On your VM you need to create that file (you'll need sudo rights) with the following contents:
NAME="Ubuntu"
VERSION="12.04 LTS, Precise Pangolin"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu precise (12.04 LTS)"
VERSION_ID="12.04"
Save it and restart the vagrant box and all should be well with the world again.
