Glue code required to get an Active Record rake task working outside of Rails

migration_status.rb

require 'rake'
require 'active_record'
require 'erb'
require 'yaml'

ActiveRecord::Tasks::DatabaseTasks.migrations_paths = [File.expand_path('db/migrate')]

module Rails
  def self.env
    'development'
  end
end

load 'active_record/railties/databases.rake'

task :environment do
  config = YAML.load(ERB.new(File.read('config/database.yml')).result)
  ActiveRecord::Base.establish_connection(config[Rails.env])
end

Rake::Task['db:migrate:status'].invoke