Recreation of a DataMapper STI/auto_upgrade bug

dm_auto_migration_bug.rb

gem 'dm-core', '0.10.0'
require 'dm-core'

module ModelMixin
  include DataMapper::Types

  def self.included(base)
    base.module_eval do
      include DataMapper::Resource
      include DataMapper::Migrations

      property :type, Discriminator
    end
  end
end

class User

  include ModelMixin

  property :id, Serial

  property :name, String

end

class Admin < User

  property :level, Integer

end

DataMapper.setup(:default, 'sqlite3:test.db')
DataMapper.auto_upgrade!

unless ARGV[0] == 'stop'
  system('ruby',File.expand_path(__FILE__),'stop')
end