无法加载此类文件-activerecord（LoadError）

Question

我正在尝试将一个非常老的应用程序从Rails 2.3.12升级到Rails 3.0.0（作为将其升级到Rails 4的起点）。 我一直在慢慢地通过删除旧宝石等方法来修复升级后发生的任何故障。

我陷入了一个似乎无法查明或解决的问题。

我正在运行Rails3，Ruby1.9.3

当我尝试运行Rails服务器时，出现以下错误：

    => Booting WEBrick
=> Rails 3.0.0 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require': cannot load such file -- activerecord (LoadError)
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/Documents/Work/Saild/saild/vendor/plugins/acts_as_commentable/lib/commentable_methods.rb:1:in `<top (required)>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/Documents/Work/Saild/saild/vendor/plugins/acts_as_commentable/lib/acts_as_commentable.rb:1:in `<top (required)>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/Documents/Work/Saild/saild/vendor/plugins/acts_as_commentable/rails/init.rb:1:in `block in <class:Plugin>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/plugin.rb:81:in `eval'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/plugin.rb:81:in `block in <class:Plugin>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/initializable.rb:25:in `instance_exec'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/initializable.rb:25:in `run'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/initializable.rb:50:in `block in run_initializers'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/initializable.rb:49:in `each'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/initializable.rb:49:in `run_initializers'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/application.rb:134:in `initialize!'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/application.rb:77:in `method_missing'
        from /home/camillavk/Documents/Work/Saild/saild/config/environment.rb:7:in `<top (required)>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'
        from /home/camillavk/Documents/Work/Saild/saild/config.ru:3:in `block in <main>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/builder.rb:46:in `instance_eval'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/builder.rb:46:in `initialize'
        from /home/camillavk/Documents/Work/Saild/saild/config.ru:1:in `new'
        from /home/camillavk/Documents/Work/Saild/saild/config.ru:1:in `<main>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/builder.rb:35:in `eval'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/builder.rb:35:in `parse_file'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/server.rb:162:in `app'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/server.rb:253:in `wrapped_app'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/rack-1.2.8/lib/rack/server.rb:204:in `start'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/commands/server.rb:65:in `start'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/commands.rb:30:in `block in <top (required)>'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/commands.rb:27:in `tap'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/railties-3.0.0/lib/rails/commands.rb:27:in `<top (required)>'
        from script/rails:6:in `require'
        from script/rails:6:in `<main>'

我的Gemfile看起来像这样：

source 'https://rubygems.org'

gem "rails", "3.0.0"

gem "airbrake"
gem "aws-s3"
gem "bj"
gem "bundler", "~> 1.0.0"
gem "calendar_date_select", "1.15"
gem "cancan", "1.2.0"
gem "carmen"
gem 'comma', '0.4.1'
gem 'exifr'
# factory_girl 1.2.4 wasn't working with Rails 3 - consider an upgrade to factory_girl_rails?
# gem "factory_girl", "1.2.4"
gem 'fastercsv'
gem "geokit"
gem "haml"
gem "hpricot"
gem 'hoptoad_notifier'
gem "jrails"
gem "libxml-ruby", "2.4.0"
gem "memcached", "~> 1.8.0"
#memcached no longer works?
gem 'dalli'
# Not sure why we have this if we're using SQLite3
gem "mysql2", "~> 0.2.6"
#TODO: changed by almazom
gem "rake", "0.8.4"
gem 'recurly'
gem "rdoc"
gem "rmagick"
gem "rspreedly"
gem "rubyzip"
gem 'sass'
#need to use simplecov when upgrading to ruby 2 as rcov doesn't work
gem "simplecov"
gem 'sqlite3'
# tmail no longer included in rails 3?
gem 'tmail'
gem "will_paginate", "2.3.16"
gem 'yaml_db'

group :development, :test do
  gem 'test-unit', '1.2.3'
  gem 'rspec', '1.3.2'
  gem 'rspec-rails', '~> 1.3.4'
end

group :test do
  gem 'capybara', '0.3.5'
  gem 'cucumber', '1.1.2'
  gem 'cucumber-rails', :git => "git://github.com/RKelln/cucumber-rails.git", :branch => "0.3.2-capybara-fix"
  gem 'database_cleaner'
end

升级到Rails 3之前，是否有人遇到过此问题？ 我在Google上找不到任何有关此事的...。

还是有人对我如何查找/解决问题有建议？

提前谢谢了！

Answer 1

让我们看看您的堆栈跟踪。 堆栈跟踪从上到下读取。 如果您有函数A调用函数B调用函数C，但发生错误，则堆栈跟踪将显示

C
B
A

我们可以看到第一行都来自Rails本身：

/home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require': cannot load such file -- activerecord (LoadError)
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `block in require'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `block in load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:591:in `new_constants_in'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:225:in `load_dependency'
        from /home/camillavk/.rvm/gems/ruby-1.9.3-p551@rails3/gems/activesupport-3.0.0/lib/active_support/dependencies.rb:239:in `require'

由于Rails本身通常不太可能是罪魁祸首，因此我们寻找第一行来自其他地方-您自己的代码或第三方库。

下一行就是：

        from /home/camillavk/Documents/Work/Saild/saild/vendor/plugins/acts_as_commentable/lib/commentable_methods.rb:1:in `<top (required)>'

我们看到它是在vendor/plugins的代码，使它成为一个古老的Rails 2.3风格的插件。 它们已在Rails 3中弃用，并完全停止了在Rails 4中的工作。它们被通过您的Gemfile和Bundler添加的“ Gem插件”代替，而不是vendor/plugins 。

因此， acts_as_commentable是元凶。 Github项目页面显示了一个特别适用于Rails 3的版本，因此删除旧插件并用Gem替换它可以使您很好地解决此问题。