Error

==  TestingAgain: migrating ===================================================
#<User:0x000000025e8bf0>
#<User:0x000000025e7688>
#<User:0x00000003a93c08>
#<User:0x00000003a928f8>
rake aborted!
An error has occurred, this and all later migrations canceled:

uninitialized constant User::Pet/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/inheritance.rb:111:in `compute_type'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/reflection.rb:172:in `klass'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/association.rb:117:in `klass'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/association.rb:123:in `target_scope'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/association.rb:87:in `scoped'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/collection_association.rb:573:in `first_or_last'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/collection_association.rb:101:in `first'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/associations/collection_proxy.rb:46:in `first'
/home/deploy/test/tressonia/db/migrate/20130625073116_testing_again.rb:9:in `block in up'
/home/deploy/test/tressonia/db/migrate/20130625073116_testing_again.rb:8:in `each'
/home/deploy/test/tressonia/db/migrate/20130625073116_testing_again.rb:8:in `up'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:410:in `block (2 levels) in migrate'
/home/deploy/.rbenv/versions/1.9.3-p392/lib/ruby/1.9.1/benchmark.rb:280:in `measure'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:410:in `block in migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:129:in `with_connection'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:389:in `migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:528:in `migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:720:in `block (2 levels) in migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `call'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `block in ddl_transaction'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/transactions.rb:208:in `transaction'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:775:in `ddl_transaction'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:719:in `block in migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:700:in `each'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:700:in `migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:570:in `up'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/migration.rb:551:in `migrate'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/activerecord-3.2.13/lib/active_record/railties/databases.rake:193:in `block (2 levels) in <top (required)>'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:236:in `call'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:236:in `block in execute'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:231:in `each'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:231:in `execute'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:175:in `block in invoke_with_call_chain'
/home/deploy/.rbenv/versions/1.9.3-p392/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:168:in `invoke_with_call_chain'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/task.rb:161:in `invoke'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:149:in `invoke_task'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:106:in `each'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:106:in `block in top_level'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:115:in `run_with_threads'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:100:in `top_level'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:78:in `block in run'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:165:in `standard_exception_handling'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/lib/rake/application.rb:75:in `run'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/gems/rake-10.1.0/bin/rake:33:in `<top (required)>'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/bin/rake:23:in `load'
/home/deploy/test/tressonia/vendor/bundle/ruby/1.9.1/bin/rake:23:in `<main>'
Tasks: TOP => db:migrate

migration.rb

class TestingAgain < ActiveRecord::Migration
  def up
    User.first.pets
    User.all.first.pets
    User.all.each do |user|
      puts user.to_s
    end
    User.all.each do |user|
      puts user.pets.first.to_s
    end
    puts User.all.first.pets.to_s
  end

  def down
  end
end