Old Ruby bug is recurring in my Ruby on Rails app, related to Class.create and delayed_job

Question

The bug is many months old, here:

http://www.ruby-forum.com/topic/1094002

Two links in that which show code changes:

https://github.com/godfat/ruby/commit/f4e0e8f781b05c767ad2472a43a4ed0727a75708 https://github.com/godfat/ruby/commit/c7a6cf975d88828c2ed27d253f41c480f9b66ad6

I have Ruby 1.9.2 and rvm. I would have pasted those changes into the appropriate files, but I don't know how.

This worked a few days ago. I can't do Ruby on Rails commands like:

>> User.create :username => "a", :password => "a"

Here is the error message:

ArgumentError: wrong number of arguments(1 for 0)
from /Users/RedApple/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:48:in `method'
from /Users/RedApple/.rvm/rubies/ruby-1.9.2 p290/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:48:in `accept'
from /Users/RedApple/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:36:in `<<'
from /Users/RedApple/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/psych.rb:165:in `dump'
from /Users/RedApple/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/psych/core_ext.rb:13:in `psych_to_yaml'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-2.0.4/lib/delayed/backend/base.rb:57:in `payload_object='
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2918:in `block in assign_attributes'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2914:in `each'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2914:in `assign_attributes'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2787:in `attributes='
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2477:in `initialize'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:725:in `new'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:725:in `create'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/delayed_job-2.0.4/lib/delayed/message_sending.rb:9:in `method_missing'
from /Users/RedApple/S/app/models/user.rb:29:in `block in <class:User>'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-2.3.14/lib/active_support/callbacks.rb:182:in `call'
... 7 levels...
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/callbacks.rb:267:in `create_with_callbacks'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2927:in `create_or_update'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/callbacks.rb:250:in `create_or_update_with_callbacks'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:2577:in `save'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/validations.rb:1089:in `save_with_validation'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/dirty.rb:79:in `save_with_dirty'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:229:in `block in with_transaction_returning_status'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/connection_adapters/abstract/database_statements.rb:136:in `transaction'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:182:in `transaction'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:228:in `with_transaction_returning_status'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:196:in `block in save_with_transactions'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:208:in `rollback_active_record_state!'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/transactions.rb:196:in `save_with_transactions'
from /Users/RedApple/.rvm/gems/ruby-1.9.2-p290/gems/activerecord-2.3.14/lib/active_record/base.rb:727:in `create'
from (irb):1
from /Users/RedApple/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'>

Line 28-30 in user.rb:

after_create do |user|
  user.delay( :priority => -15 ).seed
end

I am dead in the water without this. Can anyone help?

Answer 1

Delayed Job and the Ruby 1.9.2 YAML parser (Psych) are unfortunately not compatible.

Switch back to the previous YAML parser (Syck) by adding this to your config/application.rb, just below the call to Bundler.require:

YAML::ENGINE.yamler = "syck" if RUBY_VERSION >= "1.9.2"