Não é possível migrar o banco de dados após o andaime. Seção 2.2 Tutorial do Ruby on Rails Michael Hartl

Estou trabalhando no tutorial do Hartl ruby on rails (seção 2.2) e estou tendo problemas para migrar o banco de dados. Tudo parecia estar funcionando, e então eu corrirails generate scaffold User name:string email:string Depois tentei executar o pacote executável rake db: migrate e recebi a mensagem de erro abaixo:

$ bundle exec rake db:migrate
                                                                                 == 20141125234257 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0079s
== 20141125234257 CreateUsers: migrated (0.0080s) =============================

rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

wrong number of arguments (1 for 0)/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `initialize'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `new'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `substitute_at'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:97:in `block in substitute_values'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `each'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `each_with_index'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `substitute_values'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:56:in `insert'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:521:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/counter_cache.rb:139:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/attribute_methods/dirty.rb:122:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:306:in `block in _create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `call'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `_run_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:734:in `_run_create_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:306:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/timestamp.rb:57:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:501:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:302:in `block in create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `call'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `_run_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:734:in `_run_save_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:302:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:142:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/validations.rb:42:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:289:in `block in save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:345:in `block in with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:218:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:342:in `with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:289:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:51:in `create!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1015:in `record_version_state_after_migrating'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:985:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1030:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/transaction.rb:188:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:218:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1030:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:983:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:945:in `block in migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:941:in `each'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:941:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:813:in `up'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:791:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/railties/databases.rake:44:in `block (2 levels) in <top (required)>'
ArgumentError: wrong number of arguments (1 for 0)
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `initialize'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `new'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract_adapter.rb:271:in `substitute_at'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:97:in `block in substitute_values'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `each'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `each_with_index'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96:in `substitute_values'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:56:in `insert'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:521:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/counter_cache.rb:139:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/attribute_methods/dirty.rb:122:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:306:in `block in _create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `call'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `_run_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:734:in `_run_create_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:306:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/timestamp.rb:57:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:501:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:302:in `block in create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `call'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:88:in `_run_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb:734:in `_run_save_callbacks'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:302:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:142:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/validations.rb:42:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:289:in `block in save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:345:in `block in with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:218:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:342:in `with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:289:in `save!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb:51:in `create!'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1015:in `record_version_state_after_migrating'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:985:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1030:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/transaction.rb:188:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/transactions.rb:218:in `transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:1030:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:983:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:945:in `block in migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:941:in `each'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:941:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:813:in `up'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/migration.rb:791:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
/usr/local/rvm/gems/ruby-2.1.4@rails4/gems/activerecord-4.2.0.beta4/lib/active_record/railties/databases.rake:44:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

Tentei voltar para uma confirmação anterior e executar tudo novamente, mas recebo a mesma mensagem de erro. Há mais arquivos que devo adicionar que possam ajudar com isso?