Undefined variable using Rails 4 master and Foundation (run rake assets:precompile)

application.rb

require "bundler"
Bundler.require

class MyApp < Rails::Application
	config.assets.precompile = ["test.css"]
	config.assets.paths += ["."]
	config.assets.paths += Compass::Frameworks::ALL.map {|framework| framework.stylesheets_directory}
	config.assets.paths << File.join(Foundation::Engine.root, "scss")
end

MyApp.initialize!

Gemfile

source :rubygems

gem "rails", github: "rails/rails"
gem "journey", github: "rails/journey"
gem "activerecord-deprecated_finders", github: "rails/activerecord-deprecated_finders"
gem "sprockets-rails", github: "rails/sprockets-rails"
gem "zurb-foundation"

Rakefile

require File.expand_path('../application', __FILE__)
require 'rake'

MyApp::load_tasks

test.scss

@import "foundation";