chained_inclusions_broken.rb

module SecondLevelModule 
  def self.included(base)
    base.extend ClassMethods
  end

  def second_level_instance_method; 'ok'; end

  module ClassMethods
    def second_level_class_method; 'ok'; end
  end 
end

module FirstLevelModule 
  def self.included(base)
    base.extend ClassMethods
  end

  def first_level_instance_method; 'ok'; end

  module ClassMethods
    def first_level_class_method; 'ok'; end
  end
  
  include SecondLevelModule
end

class BaseClass
  include FirstLevelModule
end