nil：NilClass的未定义方法'children'

Question

好的。 我在这里不懂事。

我有一个大约三个星期没有使用过的Rails应用程序...但是当我离开时，它在任何地方都没有产生此错误。

我正在使用许多宝石的最新版本，但它们似乎都可以正常工作。 我现在在ruby1.9下工作，所以我升级了一些东西来匹配它。 我有理由确定，这是自3周前以来唯一要更改的重要内容。

许多页面可以很好地呈现，但是一页失败，出现NoMethodError“ nil：NilClass的未定义方法'children'”和以下看似仅框架的堆栈跟踪。 对于有问题的页面，我已经注释掉了整个haml页面，控制器方法，所有before_filters，所有application_controller以及其他一些内容。

我将haml和指南针的等级降级，怀疑它们是罪魁祸首，即使其他页面效果很好。 我现在想回到所有分支上的稳定分支，除了我认为是devise，但这似乎不是问题的一部分，因为登录可以正常工作。

activesupport (3.0.7) lib/active_support/whiny_nil.rb:48:in `method_missing'
haml (3.1.1) lib/haml/parser.rb:151:in `parse'
haml (3.1.1) lib/haml/engine.rb:124:in `initialize'
haml (3.1.1) lib/haml/template/plugin.rb:34:in `new'
haml (3.1.1) lib/haml/template/plugin.rb:34:in `compile'
haml (3.1.1) lib/haml/template/plugin.rb:39:in `call'
actionpack (3.0.7) lib/action_view/template.rb:226:in `compile'
actionpack (3.0.7) lib/action_view/template.rb:134:in `block in render'
activesupport (3.0.7) lib/active_support/notifications.rb:54:in `instrument'
actionpack (3.0.7) lib/action_view/template.rb:127:in `render'
actionpack (3.0.7) lib/action_view/render/rendering.rb:59:in `block in _render_template'
activesupport (3.0.7) lib/active_support/notifications.rb:52:in `block in instrument'
activesupport (3.0.7) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.0.7) lib/active_support/notifications.rb:52:in `instrument'
actionpack (3.0.7) lib/action_view/render/rendering.rb:56:in `_render_template'
actionpack (3.0.7) lib/action_view/render/rendering.rb:26:in `render'
haml (3.1.1) lib/haml/helpers/action_view_mods.rb:13:in `render_with_haml'
actionpack (3.0.7) lib/abstract_controller/rendering.rb:115:in `_render_template'
actionpack (3.0.7) lib/abstract_controller/rendering.rb:109:in `render_to_body'
actionpack (3.0.7) lib/action_controller/metal/renderers.rb:47:in `render_to_body'
actionpack (3.0.7) lib/action_controller/metal/compatibility.rb:55:in `render_to_body'
actionpack (3.0.7) lib/abstract_controller/rendering.rb:102:in `render_to_string'
actionpack (3.0.7) lib/abstract_controller/rendering.rb:93:in `render'
actionpack (3.0.7) lib/action_controller/metal/rendering.rb:17:in `render'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:40:in `block (2 levels) in render'
activesupport (3.0.7) lib/active_support/core_ext/benchmark.rb:5:in `block in ms'
/Users/DeVeLoPeR/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/benchmark.rb:309:in `realtime'
activesupport (3.0.7) lib/active_support/core_ext/benchmark.rb:5:in `ms'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:40:in `block in render'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:78:in `cleanup_view_runtime'
activerecord (3.0.7) lib/active_record/railties/controller_runtime.rb:15:in `cleanup_view_runtime'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:39:in `render'
actionpack (3.0.7) lib/action_controller/metal/implicit_render.rb:14:in `default_render'
actionpack (3.0.7) lib/action_controller/metal/implicit_render.rb:6:in `send_action'
actionpack (3.0.7) lib/abstract_controller/base.rb:150:in `process_action'
actionpack (3.0.7) lib/action_controller/metal/rendering.rb:11:in `process_action'
actionpack (3.0.7) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.0.7) lib/active_support/callbacks.rb:436:in `_run__1376965243214072245__process_action__2201785587746499238__callbacks'
activesupport (3.0.7) lib/active_support/callbacks.rb:410:in `_run_process_action_callbacks'
activesupport (3.0.7) lib/active_support/callbacks.rb:94:in `run_callbacks'
actionpack (3.0.7) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.0.7) lib/active_support/notifications.rb:52:in `block in instrument'
activesupport (3.0.7) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
activesupport (3.0.7) lib/active_support/notifications.rb:52:in `instrument'
actionpack (3.0.7) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.0.7) lib/action_controller/metal/rescue.rb:17:in `process_action'
actionpack (3.0.7) lib/abstract_controller/base.rb:119:in `process'
actionpack (3.0.7) lib/abstract_controller/rendering.rb:41:in `process'
actionpack (3.0.7) lib/action_controller/metal.rb:138:in `dispatch'
actionpack (3.0.7) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.0.7) lib/action_controller/metal.rb:178:in `block in action'
actionpack (3.0.7) lib/action_dispatch/routing/route_set.rb:62:in `call'
actionpack (3.0.7) lib/action_dispatch/routing/route_set.rb:62:in `dispatch'
actionpack (3.0.7) lib/action_dispatch/routing/route_set.rb:27:in `call'
rack-mount (0.6.14) lib/rack/mount/route_set.rb:148:in `block in call'
rack-mount (0.6.14) lib/rack/mount/code_generation.rb:93:in `block in recognize'
rack-mount (0.6.14) lib/rack/mount/code_generation.rb:68:in `optimized_each'
rack-mount (0.6.14) lib/rack/mount/code_generation.rb:92:in `recognize'
rack-mount (0.6.14) lib/rack/mount/route_set.rb:139:in `call'
actionpack (3.0.7) lib/action_dispatch/routing/route_set.rb:493:in `call'
sass (3.1.1) lib/sass/plugin/rack.rb:54:in `call'
warden (1.0.4) lib/warden/manager.rb:35:in `block in call'
warden (1.0.4) lib/warden/manager.rb:34:in `catch'
warden (1.0.4) lib/warden/manager.rb:34:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/head.rb:14:in `call'
rack (1.2.2) lib/rack/methodoverride.rb:24:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/flash.rb:182:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/session/abstract_store.rb:149:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/cookies.rb:302:in `call'
activerecord (3.0.7) lib/active_record/query_cache.rb:32:in `block in call'
activerecord (3.0.7) lib/active_record/connection_adapters/abstract/query_cache.rb:28:in `cache'
activerecord (3.0.7) lib/active_record/query_cache.rb:12:in `cache'
activerecord (3.0.7) lib/active_record/query_cache.rb:31:in `call'
activerecord (3.0.7) lib/active_record/connection_adapters/abstract/connection_pool.rb:354:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/callbacks.rb:46:in `block in call'
activesupport (3.0.7) lib/active_support/callbacks.rb:416:in `_run_call_callbacks'
actionpack (3.0.7) lib/action_dispatch/middleware/callbacks.rb:44:in `call'
rack (1.2.2) lib/rack/sendfile.rb:107:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/remote_ip.rb:48:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/show_exceptions.rb:47:in `call'
railties (3.0.7) lib/rails/rack/logger.rb:13:in `call'
rack (1.2.2) lib/rack/runtime.rb:17:in `call'
activesupport (3.0.7) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.2.2) lib/rack/lock.rb:11:in `block in call'
<internal:prelude>:10:in `synchronize'
rack (1.2.2) lib/rack/lock.rb:11:in `call'
actionpack (3.0.7) lib/action_dispatch/middleware/static.rb:30:in `call'
railties (3.0.7) lib/rails/application.rb:168:in `call'
railties (3.0.7) lib/rails/application.rb:77:in `method_missing'
railties (3.0.7) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.2.2) lib/rack/content_length.rb:13:in `call'
rack (1.2.2) lib/rack/handler/webrick.rb:52:in `service'
/Users/DeVeLoPeR/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
/Users/DeVeLoPeR/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
/Users/DeVeLoPeR/.rvm/rubies/ruby-1.9.2-p180/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'

我开始认为对红宝石1.9.2的更改导致了这种情况，但我不知道会如何。 我将回到ruby 1.8.7，以便我可以再次工作（希望），但是我们的生产服务器运行1.9.2，因此有时需要它。

任何想法表示赞赏。

谢谢

编辑降级到Ruby1.8.7无效。 我也在没有RVM的另一台计算机上尝试过。

根据要求编辑 Gemfile：

source 'http://rubygems.org'

gem 'rails', '3.0.7'

gem 'sqlite3-ruby', :require => 'sqlite3'
gem 'mysql'

gem "will_paginate", "~> 3.0.pre2"
gem 'activemerchant'

gem 'devise', '1.1.9'

gem 'ruby-debug'
gem 'sslrequirement'
gem 'cancan'
gem 'rmagick'
gem 'carrierwave', "~> 0.5.3"
gem 'haml'
gem 'compass'
#gem 'mongrel'
gem 'jquery-rails'

group :development, :test do
  gem 'webrat'
  gem 'wirble'
end

Answer 1

您是否使用HAML注释（-＃）？ 删除它们对我有用。