included do |mod| ... end としてincludeされたモジュールの情報を使いたい。

concern_patch.rb

module ActiveSupport
  module Concern
    def append_features(base)
      if base.instance_variable_defined?("@_dependencies")
        base.instance_variable_get("@_dependencies") << self
        return false
      else
        return false if base < self
        @_dependencies.each { |dep| base.send(:include, dep) }
        super
        base.extend const_get("ClassMethods") if const_defined?("ClassMethods")
        if instance_variable_defined?("@_included_block")
          if @_included_block.is_a? Array
            base.class_exec(@_included_block[0], &@_included_block[1]) # give module as first argument
          else
            base.class_exec(&@_included_block)
          end
        end
      end
    end

    def included(base = nil, &block)
      if base.nil?
        @_included_block = [self, block] # store module (= self)
      else
        super
      end
    end
  end
end