dm-bug.rb

#!/usr/bin/env ruby -KU
require "rubygems"
require "dm-core"

DataMapper.setup(:default, 'sqlite3::memory:')
DataMapper.setup(:second,  "sqlite3:///#{File.dirname(__FILE__)}/test.db")

class Customer
  include DataMapper::Resource
  def self.default_repository_name ; :default ; end
  
  property :id,   Serial
  property :name, String
  
  def contact
    DataMapper.repository(:second) do
      Contact.first(:name => name)
    end
  end
end

class Contact
  include DataMapper::Resource
  def self.default_repository_name ; :second ; end
  
  property :id,   Serial
  property :name, String
end

Customer.auto_migrate!(:default)
Contact.auto_migrate!(:second)

# Customer.create(:name => "carl") # DataMapper.repository(:default) {  }
Contact.create(:name => "carl")  # DataMapper.repository(:second)  {   }

customer = Customer.new(:name => "carl")
customer.contact

puts customer.class.repositories.inspect