升级到Rails 3.2.2：如何解决与Delayed Job gem相关的’未定义的Syck :: DomainType方法’错误？
我从3.1.0运行Ruby on Rails 3.2.2。 我有这个问题
undefined method send_register_email\' for #\n//.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/performable_mailer.rb:6:in perform ... 有许多其他人试图解决的DelayedJobgem：有人成功，其他人没有。 如果我尝试了我在网上找到的所有解决方案，那么我属于后一类。
这时，在我的Gemfile中，我有：
gem 'rails', '3.2.2' gem "rake" ... gem 'delayed_job_active_record' ...
在升级Rails之前，在我的Gemfile中我有：
gem 'rails', '~> 3.1.0' gem "rake" ... # I also used the following statement by running Rails 3.2.2 but it didn't work. gem 'delayed_job' ...
为了发送电子邮件，在我的控制器中，我使用以下代码链接：
::Users::Mailer.delay.send_register_email(@user)
在我的APPLICATION_ROOT/app/mailers/users/mailer.rb文件中，我有：
class Users::Mailer < ActionMailer::Base ... def send_register_email(user) ... end end
在更新到Rails 3.2.2之前，所有工作都正常。 现在我在介绍文本中得到了上面提到的错误。 我该如何尝试解决延迟工作问题？
我注意到在与delayed_job_active_record gem相关的数据库表中，应该是一个名为’queue’的列（有关更多信息，请参阅官方文档中的“Gory Details”部分）。 但是，由于我使用gem 'delayed_job'它存在于该数据库表中。 可能是那个问题？
我注意到的另一件事是以下（但我认为这不是问题，现在）：
$ rake jobs:work DEPRECATION WARNING: You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on this: http://weblog.rubyonrails.org/2012/01/04/rails-3-2-0-rc2-has-been-released. (called from at //Rakefile:7) DEPRECATION WARNING: You have Rails 2.3-style plugins in vendor/plugins! Support for these plugins will be removed in Rails 4.0. Move them out and bundle them in your Gemfile, or fold them in to your app as lib/myplugin/* and config/initializers/myplugin.rb. See the release notes for more on this: http://weblog.rubyonrails.org/2012/01/04/rails-3-2-0-rc2-has-been-released. (called from at //Rakefile:7) [Worker(host:.local pid:76826)] Starting job worker
以下是DelayedJob last_error数据库表列中的内容：
{undefined method `send_register_email' for # //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/performable_mailer.rb:6:in `perform' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/backend/base.rb:94:in `block in invoke_job' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `call' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `block in initialize' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `call' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `execute' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:38:in `run_callbacks' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/backend/base.rb:91:in `invoke_job' //.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:162:in `block (2 levels) in run' //.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/timeout.rb:58:in `timeout' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:162:in `block in run' ///.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/benchmark.rb:310:in `realtime' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:161:in `run' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:218:in `block in reserve_and_run_one_job' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `block in initialize' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `execute' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:38:in `run_callbacks' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:218:in `reserve_and_run_one_job' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:146:in `block in work_off' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:145:in `times' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:145:in `work_off' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:117:in `block (4 levels) in start' ///.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/benchmark.rb:310:in `realtime' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:116:in `block (3 levels) in start' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `block in initialize' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `execute' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:38:in `run_callbacks' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:113:in `block (2 levels) in start' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:112:in `loop' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:112:in `block in start' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/plugins/clear_locks.rb:7:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/plugins/clear_locks.rb:7:in `block (2 levels) in ' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:78:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:78:in `block (2 levels) in add' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:60:in `block in initialize' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:78:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:78:in `block in add' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `call' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:65:in `execute' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/lifecycle.rb:38:in `run_callbacks' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/worker.rb:111:in `start' ///.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-3.0.1/lib/delayed/tasks.rb:9:in `block (2 levels) in ' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain' ///.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run' ///.rvm/gems/ruby-1.9.2-p290@global/gems/rake-0.9.2.2/bin/rake:33:in `' ///.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `load' ///.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `'
我们通过确保在初始化时将YAML解析器设置为Syck是绝对首要的事情，设法解决了我们应用中的Syck / Psych古怪问题。 你有时会遇到问题的原因是DelayedJob根据你正在使用的YAML解析器进行不同的初始化，如果解析器在初始化期间发生了变化，则DelayedJob可能会错误。
将它添加到boot.rb的最顶层，看看它是否有帮助：
require 'yaml' YAML::ENGINE.yamler = 'syck'
如果您正在使用bundler尝试使用“bundle exec”为脚本或rake任务添加前缀，例如
bundle exec script/delayed_job -n 2 start
它为我们做了伎俩。