rake test:prepare 在 Rails 4.0.8 中失败

Question

当我注意到 rake test:prepare 抛出一个奇怪的 FATAL: database "postgres" does not exist 错误时，我正在测试我的应用程序（使用 rspec）。更奇怪的是，我的测试运行得很好。

但是，每当我使用rake test:prepare --trace（使用rake db:migrate 之后）时，我都会收到此错误，并且在尝试rake db:create RAILS_ENV=test 和rake db:drop RAILS_ENV=test 时也会收到相同的错误。知道我可能忽略了什么吗？

这是有问题的错误：

** Invoke test:prepare (first_time)
** Invoke db:test:prepare (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:test:prepare
** Invoke db:test:load (first_time)
** Invoke db:test:purge (first_time)
** Invoke environment
** Invoke db:load_config
** Execute db:test:purge
rake aborted!

PG::Error: FATAL: database "postgres" does not exist

/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:855:in `initialize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:855:in `new'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:855:in `connect'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:556:in `initialize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:440:in `new_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:450:in `checkout_new_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:421:in `acquire_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:356:in `block in checkout'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `checkout'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_handling.rb:79:in `retrieve_connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/connection_handling.rb:53:in `connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/tasks/postgresql_database_tasks.rb:30:in `drop'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/tasks/postgresql_database_tasks.rb:43:in `purge'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/tasks/database_tasks.rb:137:in `purge'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/railties/databases.rake:365:in `block (3 levels) in <top (required)>'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:201:in `block in invoke_prerequisites'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:199:in `each'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:199:in `invoke_prerequisites'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:178:in `block in invoke_with_call_chain'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/activerecord-4.0.8/lib/active_record/railties/databases.rake:371:in `block (3 levels) in <top (required)>'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:201:in `block in invoke_prerequisites'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:199:in `each'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:199:in `invoke_prerequisites'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:178:in `block in invoke_with_call_chain'
/Users/Wilhelm/.rvm/rubies/ruby-2.0.0-p481/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/bin/rake:23:in `load'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/bin/rake:23:in `<main>'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/bin/ruby_executable_hooks:15:in `eval'
/Users/Wilhelm/.rvm/gems/ruby-2.0.0-p481@rails_4_0/bin/ruby_executable_hooks:15:in `<main>'

Tasks: TOP => db:test:load => db:test:purge

这是我的测试环境的样子（根据我的 gemfile）：

gem 'rails', '4.0.8'
gem 'pg', '0.15.1'

group :development, :test do
    gem 'rspec-rails', '2.13.1'
end

group :test do
    gem 'selenium-webdriver', '2.35.1'
    gem 'capybara', '2.1.0'
end

编辑

这是我的database.yml 文件的样子：

development:
  adapter: postgresql
  endoding: unicode
  database: myapp_development
  pool: 5
  timeout: 5000
  hostname: localhost

test:
  adapter: postgresql
  endoding: unicode
  database: myapp_test
  pool: 5
  timeout: 5000
  hostname: localhost

production:
  adapter: postgresql
  database: myapp_production
  pool: 5
  timeout: 5000

Answer 1

尝试使用 Postgres 客户端（例如 pgAdmin3，或命令行上的 psql）尝试在您的服务器上创建名为“postgres”的数据库。不要尝试使用 Rails rake 任务来执行此操作 - 它们可能会因为同样的原因而失败。

使用 psql 你可以试试：

CREATE DATABASE postgres;

如果您喜欢 GUI，也可以使用 pgAdmin3（Postgres 免费）。

您需要以具有创建数据库的适当权限的用户身份登录。

据我了解，该数据库是由较新版本的 Postgres 自动创建的。它不需要桌子。您的 Postgres 实例可能没有它，或者它可能已被删除或重命名，但 Rails 使用的数据库适配器出于某种原因需要它。