Vagrant file for a private WebPagetest instance

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

# Vagrantfile API/syntax version. Don't touch unless you know what you're doing!
VAGRANTFILE_API_VERSION = "2"

Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
  # All Vagrant configuration is done here. The most common configuration
  # options are documented and commented below. For a complete reference,
  # please see the online documentation at vagrantup.com.

  # Every Vagrant virtual environment requires a box to build off of.
  config.vm.box = "webpagetest-2-12"

  # The url from where the 'config.vm.box' box will be fetched if it
  # doesn't already exist on the user's system.
  config.vm.box_url = "https://dl.dropboxusercontent.com/u/3249984/vagrant_boxes/webpagetest.box"

  # Create a forwarded port mapping which allows access to a specific port
  # within the machine from a port on the host machine. In the example below,
  # accessing "localhost:8080" will access port 80 on the guest machine.
  config.vm.network :forwarded_port, guest: 80, host: 8080

end

I can start a test on localhost, but test just waits in queue, never seems to start executing. How can I debug this?