未初始化的常量ActiveModel :: Observing（NameError）

Question

我开发了一个在rails上使用ruby的web应用程序。我已经将我的rails版本从3.2升级到4.0，并且在启动我的服务器时出现以下错误。

错误：

/home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/dynamoid-0.6.1.1/lib/dynamoid /config.rb:11:in <module:Config>': uninitialized constant ActiveModel::Observing (NameError) from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/dynamoid-0.6.1.1/lib/dynamoid/config.rb:8:in' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/dynamoid-0.6.1.1/lib/dynamoid/config .RB：5：<top (required)>' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/1.9.1/rubygems/custom_require.rb:36:in需要 ' 从/home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/1.9.1/rubygems/custom_require.rb:36:in require' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/dynamoid-0.6.1.1/lib/dynamoid.rb:21:in' 从/home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:76:in require' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:76:in block（2 levels） in require' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:74:in each' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:74:in请求' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:63:in each' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:63:in需要' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/bundler-1.3.5/lib/bundler.rb:132:in require' from /home/lakhwani/FCLaunchRequirement/src/FCLaunchRequirementWebsite/rails-root/config/application.rb:88:in' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/1.9.1/rubyg EMS/custom_require.rb：36：在require' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/1.9.1/rubygems/custom_require.rb:36:in需要 ' 从/home/lakhwani/FCLaunchRequirement/src/FCLaunchRequirementWebsite/rails-root/config/environment.rb:6:in <top (required)>' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/1.9.1/rubygems/custom_require.rb:36:in需要' 从/家/ lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby​​1.9/1.9.1/ruby​​gems/custom_require.rb：36：在require' from /home/lakhwani/FCLaunchRequirement/src/FCLaunchRequirementWebsite/rails-root/config.ru:3:in区块中的' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/ gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb：55：in instance_eval' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:55:in initialize' from /home/lakhwani/FCLaunchRequirement/src/FCLaunchRequirementWebsite/rails-root/config.ru:in new' from /home/lakhwani/FCLaunchRequirement/src/FCLaunchRequirementWebsite/rails-root/config.ru:in' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:49:in eval' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:49:in new_from_string' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/builder.rb:40:in parse_file' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:277:in build_app_and_options_from_config' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:199:in app' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:314:in wrapped_app ' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:250:in start' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:141:in start' 从/home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/ruby1.9/gems/1.9.1/gems/rack-1.5.2/bin/rackup:4:in <top (required)>' from /home/lakhwani/FCLaunchRequirement/env/FCLaunchRequirementWebsite-1.0/runtime/bin/rackup:23:in负载” 从/家/ lakhwani/FCLaunchRequirement/ENV/FCLaunchRe quirementWebsite-1.0/runtime/bin/rackup：23：在<main>' /home/lakhwani/FCLaunchRequirement/env/BrazilRake-1.1/runtime/ruby2.1.x/lib/ruby/site_ruby/2.1.0/amazon/brazil/ruby.rb:98:in exec_build_script'：命令退出状态1！从/home/lakhwani/FCLaunchRequirement/env/BrazilRake-1.1/runtime/bin/brazilrake:61:in block in <main>' from /home/lakhwani/FCLaunchRequirement/env/BrazilRake-1.1/runtime/bin/brazilrake:48:in每个” 从/home/lakhwani/FCLaunchRequirement/env/BrazilRake-1.1/runtime/bin/brazilrake（RuntimeError） ：48：in''

任何人都可以帮我解决这个问题吗？

Answer 1

您是如何更新rails项目以使用rails 4的？对于rails 4.2及更低版本，如果您想更新它，只需在应用程序的Gemfile中添加所需的rails版本并运行rails app:update。按照here。