编辑#2:我刚刚从 4.0.1 降级回 Rails 4.0.0，它解决了问题...如果有人知道是什么原因造成的，以及如何安全地升级到 4.0 .1，请告诉我。或者这可能是应该报告的 4.0.1 或 HAML 问题？我不知道该向哪里报告...
我的 HAML View ，昨天运行良好，我没有改变，不知何故不再运行。
观点:
1 =form_for @document do |f|
2
3 =f.text_field :title, placeholder: "Title"
4
5 =f.text_field :slug, placeholder: "URL slug"
6
7 ... and more
以及它从第 1 行抛出的错误:
undefined method `[]' for nil:NilClass
@document 在 Controller 中被实例化为 Document.new。就像我说的，这段代码昨天运行良好，我没有更改 View 或 Controller 。我今天从 Rails 4.0.0 升级到 4.0.1 - 这可能是罪魁祸首吗？
我的Gemfile.lock:
GIT
remote: git://github.com/adzap/active_enum.git
revision: 280548e3954d8f9e032968dd2757b7e5862cdf49
specs:
active_enum (0.9.12)
activesupport (>= 3.0)
GIT
remote: git://github.com/sporkrb/spork-rails.git
revision: 0dd45e59d3237b4c8f9efc215b46d9c07072a95e
specs:
spork-rails (4.0.0)
rails (>= 3.0.0, < 5)
spork (>= 1.0rc0)
GEM
remote: https://rubygems.org/
specs:
actionmailer (4.0.1)
actionpack (= 4.0.1)
mail (~> 2.5.4)
actionpack (4.0.1)
activesupport (= 4.0.1)
builder (~> 3.1.0)
erubis (~> 2.7.0)
rack (~> 1.5.2)
rack-test (~> 0.6.2)
active_model_serializers (0.8.1)
activemodel (>= 3.0)
activemodel (4.0.1)
activesupport (= 4.0.1)
builder (~> 3.1.0)
activerecord (4.0.1)
activemodel (= 4.0.1)
activerecord-deprecated_finders (~> 1.0.2)
activesupport (= 4.0.1)
arel (~> 4.0.0)
activerecord-deprecated_finders (1.0.3)
activesupport (4.0.1)
i18n (~> 0.6, >= 0.6.4)
minitest (~> 4.2)
multi_json (~> 1.3)
thread_safe (~> 0.1)
tzinfo (~> 0.3.37)
annotate (2.5.0)
rake
ansi (1.4.3)
arel (4.0.1)
atomic (1.1.14)
aws-sdk (1.22.1)
json (~> 1.4)
nokogiri (>= 1.4.4, < 1.6.0)
uuidtools (~> 2.1)
bcrypt-ruby (3.1.2)
bootstrap-sass (2.3.1.0)
sass (~> 3.2)
builder (3.1.4)
capybara (2.1.0)
mime-types (>= 1.16)
nokogiri (>= 1.3.3)
rack (>= 1.0.0)
rack-test (>= 0.5.4)
xpath (~> 2.0)
capybara-webkit (1.0.0)
capybara (~> 2.0, >= 2.0.2)
json
celluloid (0.15.2)
timers (~> 1.1.0)
childprocess (0.3.9)
ffi (~> 1.0, >= 1.0.11)
climate_control (0.0.3)
activesupport (>= 3.0)
cocaine (0.5.2)
climate_control (>= 0.0.3, < 1.0)
coderay (1.0.9)
coffee-rails (4.0.0)
coffee-script (>= 2.2.0)
railties (>= 4.0.0.beta, < 5.0)
coffee-script (2.2.0)
coffee-script-source
execjs
coffee-script-source (1.5.0)
columnize (0.3.6)
database_cleaner (1.1.1)
debugger (1.6.2)
columnize (>= 0.3.1)
debugger-linecache (~> 1.2.0)
debugger-ruby_core_source (~> 1.2.3)
debugger-linecache (1.2.0)
debugger-ruby_core_source (1.2.3)
devise (3.1.1)
bcrypt-ruby (~> 3.0)
orm_adapter (~> 0.1)
railties (>= 3.2.6, < 5)
thread_safe (~> 0.1)
warden (~> 1.2.3)
diff-lcs (1.2.4)
dropbox-sdk (1.6.1)
json
erubis (2.7.0)
ethon (0.5.12)
ffi (>= 1.3.0)
mime-types (~> 1.18)
execjs (1.4.0)
multi_json (~> 1.0)
factory_girl (4.1.0)
activesupport (>= 3.0.0)
factory_girl_rails (4.1.0)
factory_girl (~> 4.1.0)
railties (>= 3.0.0)
faker (1.2.0)
i18n (~> 0.5)
fakeweb (1.3.0)
faraday (0.8.8)
multipart-post (~> 1.2.0)
ffi (1.9.0)
figaro (0.7.0)
bundler (~> 1.0)
rails (>= 3, < 5)
font-awesome-sass-rails (3.0.2.2)
railties (>= 3.1.1)
sass-rails (>= 3.1.1)
formatador (0.2.4)
guard (2.0.5)
formatador (>= 0.2.4)
listen (~> 2.0)
lumberjack (~> 1.0)
pry (>= 0.9.12)
thor (>= 0.18.1)
guard-rspec (1.2.1)
guard (>= 1.1)
guard-spork (1.5.1)
childprocess (>= 0.2.3)
guard (>= 1.1)
spork (>= 0.8.4)
haml (4.0.4)
tilt
hashie (2.0.5)
hashr (0.0.22)
hike (1.2.3)
httpauth (0.2.0)
i18n (0.6.5)
jquery-rails (3.0.1)
railties (>= 3.0, < 5.0)
thor (>= 0.14, < 2.0)
json (1.8.0)
jwt (0.1.8)
multi_json (>= 1.5)
libv8 (3.16.14.3)
listen (2.1.0)
celluloid (>= 0.15.2)
rb-fsevent (>= 0.9.3)
rb-inotify (>= 0.9)
lumberjack (1.0.4)
mail (2.5.4)
mime-types (~> 1.16)
treetop (~> 1.4.8)
method_source (0.8.2)
mime-types (1.25.1)
minitest (4.7.5)
multi_json (1.8.2)
multipart-post (1.2.0)
nokogiri (1.5.9)
oauth2 (0.8.1)
faraday (~> 0.8)
httpauth (~> 0.1)
jwt (~> 0.1.4)
multi_json (~> 1.0)
rack (~> 1.2)
omniauth (1.1.4)
hashie (>= 1.2, < 3)
rack
omniauth-github (1.1.0)
omniauth (~> 1.0)
omniauth-oauth2 (~> 1.1)
omniauth-oauth2 (1.1.1)
oauth2 (~> 0.8.0)
omniauth (~> 1.0)
orm_adapter (0.4.0)
paperclip (3.5.1)
activemodel (>= 3.0.0)
activesupport (>= 3.0.0)
cocaine (~> 0.5.0)
mime-types
pg (0.15.1)
polyglot (0.3.3)
protected_attributes (1.0.3)
activemodel (>= 4.0.0, < 5.0)
pry (0.9.12.2)
coderay (~> 1.0.5)
method_source (~> 0.8)
slop (~> 3.4)
rack (1.5.2)
rack-test (0.6.2)
rack (>= 1.0)
rails (4.0.1)
actionmailer (= 4.0.1)
actionpack (= 4.0.1)
activerecord (= 4.0.1)
activesupport (= 4.0.1)
bundler (>= 1.3.0, < 2.0)
railties (= 4.0.1)
sprockets-rails (~> 2.0.0)
rails_12factor (0.0.2)
rails_serve_static_assets
rails_stdout_logging
rails_serve_static_assets (0.0.1)
rails_stdout_logging (0.0.3)
railties (4.0.1)
actionpack (= 4.0.1)
activesupport (= 4.0.1)
rake (>= 0.8.7)
thor (>= 0.18.1, < 2.0)
rake (10.1.0)
rb-fsevent (0.9.3)
rb-inotify (0.9.2)
ffi (>= 0.5.0)
ref (1.0.5)
rest-client (1.6.7)
mime-types (>= 1.16)
rspec-core (2.14.7)
rspec-expectations (2.14.3)
diff-lcs (>= 1.1.3, < 2.0)
rspec-mocks (2.14.3)
rspec-rails (2.14.0)
actionpack (>= 3.0)
activesupport (>= 3.0)
railties (>= 3.0)
rspec-core (~> 2.14.0)
rspec-expectations (~> 2.14.0)
rspec-mocks (~> 2.14.0)
sass (3.2.12)
sass-rails (4.0.0)
railties (>= 4.0.0.beta, < 5.0)
sass (>= 3.1.10)
sprockets-rails (~> 2.0.0)
slop (3.4.6)
spork (1.0.0rc4)
sprockets (2.10.1)
hike (~> 1.2)
multi_json (~> 1.0)
rack (~> 1.0)
tilt (~> 1.1, != 1.3.0)
sprockets-rails (2.0.1)
actionpack (>= 3.0)
activesupport (>= 3.0)
sprockets (~> 2.8)
therubyracer (0.12.0)
libv8 (~> 3.16.14.0)
ref
thor (0.18.1)
thread_safe (0.1.3)
atomic
tilt (1.4.1)
timers (1.1.0)
tire (0.6.1)
activemodel (>= 3.0)
activesupport
ansi
hashr (~> 0.0.19)
multi_json (~> 1.3)
rake
rest-client (~> 1.6)
treetop (1.4.15)
polyglot
polyglot (>= 0.3.1)
typhoeus (0.6.3)
ethon (~> 0.5.11)
tzinfo (0.3.38)
uglifier (2.2.1)
execjs (>= 0.3.0)
multi_json (~> 1.0, >= 1.0.2)
uuidtools (2.1.4)
vcr (2.5.0)
warden (1.2.3)
rack (>= 1.0)
xpath (2.0.0)
nokogiri (~> 1.3)
PLATFORMS
ruby
DEPENDENCIES
active_enum!
active_model_serializers
annotate (= 2.5.0)
aws-sdk
bootstrap-sass (= 2.3.1.0)
capybara (= 2.1.0)
capybara-webkit (= 1.0.0)
childprocess (= 0.3.9)
coffee-rails (= 4.0.0)
coffee-script-source (= 1.5.0)
database_cleaner (~> 1.1.1)
debugger
devise (= 3.1.1)
dropbox-sdk (= 1.6.1)
execjs (= 1.4.0)
factory_girl_rails (= 4.1.0)
faker (~> 1.2.0)
fakeweb (= 1.3.0)
figaro (= 0.7.0)
font-awesome-sass-rails (= 3.0.2.2)
guard-rspec (= 1.2.1)
guard-spork (= 1.5.1)
haml
jquery-rails (= 3.0.1)
json (= 1.8.0)
nokogiri (= 1.5.9)
omniauth (= 1.1.4)
omniauth-github (= 1.1.0)
paperclip
pg (= 0.15.1)
protected_attributes
rails (= 4.0.1)
rails_12factor
rspec-mocks
rspec-rails
sass-rails
spork-rails!
therubyracer (= 0.12.0)
tire
typhoeus (= 0.6.3)
uglifier (>= 1.0.3)
vcr (= 2.5.0)
另外，我刚刚注意到，当我加载 Rails 控制台时，当我在 any ActiveRecord 模型上调用 .new 时出现以下错误: 对象不支持#inspect。这两个错误可能相关吗？怎么回事？
编辑:根据要求，这是完整的错误跟踪:
activerecord (4.0.1) lib/active_record/attribute_methods/read.rb:86:in `block in read_attribute'
activerecord (4.0.1) lib/active_record/attribute_methods/read.rb:84:in `fetch'
activerecord (4.0.1) lib/active_record/attribute_methods/read.rb:84:in `read_attribute'
activerecord (4.0.1) lib/active_record/attribute_methods/read.rb:59:in `__temp__9646'
activerecord (4.0.1) lib/active_record/attribute_methods/primary_key.rb:12:in `to_key'
actionpack (4.0.1) lib/action_view/record_identifier.rb:80:in `record_key_for_dom_id'
actionpack (4.0.1) lib/action_view/record_identifier.rb:62:in `dom_id'
actionpack (4.0.1) lib/action_view/helpers/form_helper.rb:448:in `apply_form_for_options!'
actionpack (4.0.1) lib/action_view/helpers/form_helper.rb:426:in `form_for'
haml (4.0.4) lib/haml/helpers/action_view_mods.rb:146:in `form_for_with_haml'
haml (4.0.4) lib/haml/helpers/action_view_xss_mods.rb:28:in `form_for_with_haml_xss'
app/views/documents/_form.html.haml:1:in `_app_views_documents__form_html_haml___2743923910659809414_70104327049600'
actionpack (4.0.1) lib/action_view/template.rb:143:in `block in render'
activesupport (4.0.1) lib/active_support/notifications.rb:161:in `instrument'
actionpack (4.0.1) lib/action_view/template.rb:141:in `render'
actionpack (4.0.1) lib/action_view/renderer/partial_renderer.rb:306:in `render_partial'
actionpack (4.0.1) lib/action_view/renderer/partial_renderer.rb:279:in `block in render'
actionpack (4.0.1) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.1) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.1) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (4.0.1) lib/action_view/renderer/partial_renderer.rb:278:in `render'
actionpack (4.0.1) lib/action_view/renderer/renderer.rb:47:in `render_partial'
actionpack (4.0.1) lib/action_view/helpers/rendering_helper.rb:27:in `render'
haml (4.0.4) lib/haml/helpers/action_view_mods.rb:10:in `block in render_with_haml'
haml (4.0.4) lib/haml/helpers.rb:89:in `non_haml'
haml (4.0.4) lib/haml/helpers/action_view_mods.rb:10:in `render_with_haml'
app/views/documents/new.html.haml:5:in `_app_views_documents_new_html_haml___1017140852746329293_70104326917800'
actionpack (4.0.1) lib/action_view/template.rb:143:in `block in render'
activesupport (4.0.1) lib/active_support/notifications.rb:161:in `instrument'
actionpack (4.0.1) lib/action_view/template.rb:141:in `render'
actionpack (4.0.1) lib/action_view/renderer/template_renderer.rb:49:in `block (2 levels) in render_template'
actionpack (4.0.1) lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.1) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.1) lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
actionpack (4.0.1) lib/action_view/renderer/template_renderer.rb:48:in `block in render_template'
actionpack (4.0.1) lib/action_view/renderer/template_renderer.rb:56:in `render_with_layout'
actionpack (4.0.1) lib/action_view/renderer/template_renderer.rb:47:in `render_template'
actionpack (4.0.1) lib/action_view/renderer/template_renderer.rb:17:in `render'
actionpack (4.0.1) lib/action_view/renderer/renderer.rb:42:in `render_template'
actionpack (4.0.1) lib/action_view/renderer/renderer.rb:23:in `render'
actionpack (4.0.1) lib/abstract_controller/rendering.rb:127:in `_render_template'
actionpack (4.0.1) lib/action_controller/metal/streaming.rb:219:in `_render_template'
actionpack (4.0.1) lib/abstract_controller/rendering.rb:120:in `render_to_body'
actionpack (4.0.1) lib/action_controller/metal/rendering.rb:33:in `render_to_body'
actionpack (4.0.1) lib/action_controller/metal/renderers.rb:26:in `render_to_body'
actionpack (4.0.1) lib/abstract_controller/rendering.rb:97:in `render'
actionpack (4.0.1) lib/action_controller/metal/rendering.rb:16:in `render'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:41:in `block (2 levels) in render'
activesupport (4.0.1) lib/active_support/core_ext/benchmark.rb:12:in `block in ms'
/Users/george/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/benchmark.rb:296:in `realtime'
activesupport (4.0.1) lib/active_support/core_ext/benchmark.rb:12:in `ms'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:41:in `block in render'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:84:in `cleanup_view_runtime'
activerecord (4.0.1) lib/active_record/railties/controller_runtime.rb:25:in `cleanup_view_runtime'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:40:in `render'
actionpack (4.0.1) lib/action_controller/metal/implicit_render.rb:10:in `default_render'
actionpack (4.0.1) lib/action_controller/metal/implicit_render.rb:5:in `send_action'
actionpack (4.0.1) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.1) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.1) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.1) lib/active_support/callbacks.rb:403:in `_run__4420817618306697940__process_action__callbacks'
activesupport (4.0.1) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.1) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.1) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.1) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.1) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.1) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.1) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (4.0.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.0.1) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.1) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.1) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.1) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.1) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.1) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.1) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.1) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.1) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.1) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.1) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.1) lib/action_dispatch/routing/route_set.rb:680:in `call'
warden (1.2.3) lib/warden/manager.rb:35:in `block in call'
warden (1.2.3) lib/warden/manager.rb:34:in `catch'
warden (1.2.3) lib/warden/manager.rb:34:in `call'
rack (1.5.2) lib/rack/etag.rb:23:in `call'
rack (1.5.2) lib/rack/conditionalget.rb:25:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/flash.rb:241:in `call'
rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/cookies.rb:486:in `call'
activerecord (4.0.1) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.0.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.1) lib/active_support/callbacks.rb:373:in `_run__3348029417397685055__call__callbacks'
activesupport (4.0.1) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.1) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/reloader.rb:64:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.1) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.1) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.0.1) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.1) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.1) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.1) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.2) lib/rack/runtime.rb:17:in `call'
activesupport (4.0.1) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
actionpack (4.0.1) lib/action_dispatch/middleware/static.rb:64:in `call'
rack (1.5.2) lib/rack/sendfile.rb:112:in `call'
railties (4.0.1) lib/rails/engine.rb:511:in `call'
railties (4.0.1) lib/rails/application.rb:97:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/george/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service'
/Users/george/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run'
/Users/george/.rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
最佳答案
看起来它与 protected_attributes gem 的版本有关，它与 rails 4.0.1 交互不利。尝试升级到 protected_attributes 1.0.5。
关于ruby-on-rails - Rails 4.0.1 和 HAML 中的 `undefined method ` [] ' for nil:NilClass`，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20237364/