エラー名
rspec --drb spec で実行すると下のようなエラーが出た。
ActiveRecord::ConnectionNotEstablished
対処法
Spork.prefork do
  ENV["RAILS_ENV"] ||= 'test'
  require File.expand_path("../../config/environment", __FILE__)
  require 'rspec/rails'
  require 'rspec/autorun'
  Dir[Rails.root.join("spec/support/**/*.rb")].each {|f| require f}
  RSpec.configure do |config|
    config.fixture_path = "#{::Rails.root}/spec/fixtures"
    config.use_transactional_fixtures = true
    config.infer_base_class_for_anonymous_controllers = false
    config.order = "random"
    config.include Capybara::DSL
    config.expect_with :rspec do |c|
      c.syntax = :expect
    end
  end
end
Spork.each_run do
  ActiveRecord::Base.shared_connection = ActiveRecord::Base.connection  # 多分ここが重要らしい!!
end
ファイルを追加する
spec/support/shared_connection.rb
class ActiveRecord::Base
  mattr_accessor :shared_connection
  @@shared_connection = nil
  def self.connection
    @@shared_connection || retrieve_connection
  end
end
これで動くようになる(^^ゞ!!