Ruby on rails 脚手架！开发环境中的未初始化常量

我使用postgresql数据库在Ubuntu10.04上安装了ror开发环境。我正在做一个生成脚手架的测试，当我得到：

<module:AppName>: uninitialized constant AppName::Rails::Application (NameError)

from /home/main/rails_app/appname/config/application.rb:12:in '<top (required)>'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:24:in 'require'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:24:in '<top (required)>'
from script/rails:6:in 'require'
from script/rails:6:in '<main>'

我记得在我不得不用

require rake/dsl_definition

编辑rakefile的时候，我遇到了一个类似的错误，但这一次它不起作用了，我被踩死了

我在谷歌上搜索时运气不佳，不知道是否有人能给我指出正确的方向

调用rake也会产生类似的错误

编辑：

我用一个新创建的db用户尝试了另一个新项目，实际上得到了这个结果

    connection_adapters/postgresql_adapter.rb:1216:in `initialize': FATAL:  Ident authentication failed for user "blog" (PG::Error)
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:1216:in `new'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:1216:in `connect'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:324:in `initialize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/railtie.rb:88:in `block in <class:Railtie>'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/daniel/rails_app/blog/config/environment.rb:5:in `<top (required)>'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:in `require'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:in `require_environment!'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:25:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

connection_adapters/postgresql_adapter.rb:1216:在'initialize'中：致命：用户“blog”的身份验证失败（PG:：Error）
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/postgresql\u adapter.rb:1216:in'new'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/postgresql\u adapter.rb:1216:in'connect'
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/postgresql\u adapter.rb:324:“初始化”中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/postgresql\u adapter.rb:28:in'new'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/postgresql\u adapter.rb:28:in`postgresql\u connection'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:315:in'new\u connection'
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:325:“签出新连接”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:247:“签出中的块（两个级别）”中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:242:in'loop'
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:242:“签出中的块”
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:在“mon_synchronize”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:239:“签出”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:102:“连接中的块”
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:在“mon_synchronize”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:101:“连接”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u pool.rb:410:“检索连接”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u specification.rb:171:“检索连接”中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/connection\u adapters/abstract/connection\u specification.rb:145:在“connection”中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active\u record/railtie.rb:88:在“块中”
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in'instance_exec'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:在“运行”中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:55:“运行中的块初始化器”
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:在'each'中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in“run_initializers”
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:136:in'initialize！'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in'method_missing'
from/home/daniel/rails\u app/blog/config/environment.rb:5:in`'
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:在'require'中
from/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:在“require_环境”中
来自/root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:25:in`'
来自脚本/rails:6:in'require'
来自脚本/rails:6:in`'

您是否使用

bundle exec运行scaffold命令

？根据您的编辑，似乎是pg身份验证错误。pg身份验证？我进入并更改了database.yml文件中列出的帐户的用户密码。还有什么地方需要我检查吗？或者我的rails项目或pg用户是否有不应该使用的名称？

    connection_adapters/postgresql_adapter.rb:1216:in `initialize': FATAL:  Ident authentication failed for user "blog" (PG::Error)
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:1216:in `new'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:1216:in `connect'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:324:in `initialize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/activerecord-3.2.13/lib/active_record/railtie.rb:88:in `block in <class:Railtie>'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `instance_exec'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:30:in `run'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:55:in `block in run_initializers'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `each'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/initializable.rb:54:in `run_initializers'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:136:in `initialize!'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /home/daniel/rails_app/blog/config/environment.rb:5:in `<top (required)>'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:in `require'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/application.rb:103:in `require_environment!'
from /root/.rbenv/versions/1.9.3-p125/lib/ruby/gems/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:25:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'