gistfile1.txt

Processing Schedule::CalendarController#confirm_date (for 127.0.0.1 at 2010-09-06 14:54:03) [POST]
  Parameters: {"{\"confirm\": true, \"date\": \"2010-05-18\", \"user_ids\": "=>{"3, 4, 14124, 1, 2"=>{", \"shop_id\": 1, \"pp\": 2639}"=>nil}}, "controller"=>"schedule/calendar", "action"=>"confirm_date", "ctx_token"=>"c1d1"}
  User Columns (4.7ms)   SHOW FIELDS FROM `users`
  User Load (0.2ms)   SELECT * FROM `users` WHERE (`users`.`id` = 5) LIMIT 1
  User: 5, ctx_token: c1d1, path /c1d1/schedule/calendar/confirm_date
  Client Columns (0.8ms)   SHOW FIELDS FROM `clients`
  Client Load (0.1ms)   SELECT * FROM `clients` WHERE (`clients`.`id` = 1) 
  Role Columns (0.6ms)   SHOW FIELDS FROM `roles`
  Role Load (0.1ms)   SELECT * FROM `roles` WHERE (`roles`.`id` = 192) 
  Shop Columns (0.7ms)   SHOW FIELDS FROM `shops`
  Shop Load (0.1ms)   SELECT * FROM `shops` WHERE (`shops`.`id` = 1) 
  PermissionType Load (0.1ms)   SELECT * FROM `permission_types` WHERE (id >= 0) ORDER BY id
  PermissionType Columns (0.5ms)   SHOW FIELDS FROM `permission_types`
Locale set to :en
  Context: cid=1, sid=1, uid=5, lang=en
  User Load (0.4ms)   SELECT * FROM `users` WHERE (`users`.`id` IN (3,4,14124,1,2)) 
  PermissionType Load (0.1ms)   SELECT * FROM `permission_types` WHERE (id >= 1) ORDER BY id
  CalendarLine Load (0.4ms)   SELECT * FROM `calendar_lines` WHERE (`calendar_lines`.`user_shop_id` = 1 AND `calendar_lines`.`date` = '2010-05-18' AND `calendar_lines`.`user_id` IN (1,2,3,4,14124)) 
  CalendarLine Columns (0.5ms)   SHOW FIELDS FROM `calendar_lines`
  SQL (0.1ms)   BEGIN
  CalendarLine Update (1.1ms)   UPDATE `calendar_lines` SET `confirmed` = 5 WHERE `id` = 1624691
  SQL (49.5ms)   COMMIT
  SQL (0.1ms)   BEGIN
  CalendarLine Update (0.2ms)   UPDATE `calendar_lines` SET `confirmed` = 5 WHERE `id` = 1624775
  SQL (31.1ms)   COMMIT
  SQL (0.0ms)   BEGIN
  CalendarLine Update (0.2ms)   UPDATE `calendar_lines` SET `confirmed` = 5 WHERE `id` = 1624523
  SQL (31.3ms)   COMMIT
  Setting Load (0.1ms)   SELECT * FROM `settings` WHERE (`settings`.`name` = 'calendar_options' AND `settings`.`context_type` = 'Client' AND `settings`.`context_id` = 1) LIMIT 1
  Setting Columns (0.8ms)   SHOW FIELDS FROM `settings`
  AbsenceType Load (0.6ms)   SELECT * FROM `absence_types` WHERE (`absence_types`.`style` = 'ab-noinput' AND `absence_types`.`context_type` = 'Client' AND `absence_types`.`context_id` = 1) LIMIT 1
  AbsenceType Columns (0.8ms)   SHOW FIELDS FROM `absence_types`
  Fragment Columns (0.5ms)   SHOW FIELDS FROM `fragments`
  SQL (0.1ms)   BEGIN
  SQL (0.0ms)   COMMIT
  SQL (0.0ms)   BEGIN
  CalendarLine Load (0.3ms)   SELECT `calendar_lines`.id FROM `calendar_lines` WHERE (`calendar_lines`.`user_id` = 4 AND `calendar_lines`.date = '2010-05-18' AND `calendar_lines`.user_shop_id = 1) LIMIT 1
  CalendarLine Create (0.3ms)   INSERT INTO `calendar_lines` (`user_shop_id`, `user_id`, `date`, `spec`, `confirmed`, `amount`) VALUES(1, 4, '2010-05-18', 'a', 5, 0.0)
  Fragment Create (2.1ms)   INSERT INTO `fragments` (`calendar_line_id`, `rel_type`, `rel_id`, `start_time`, `end_time`, `amount`, `breaks`, `color`, `description`) VALUES(2443989, 'a', 70, NULL, NULL, NULL, 0.0, NULL, NULL)
  SQL (36.4ms)   COMMIT
  SQL (0.1ms)   BEGIN
  SQL (0.0ms)   COMMIT
  SQL (0.0ms)   BEGIN
  CalendarLine Load (0.2ms)   SELECT `calendar_lines`.id FROM `calendar_lines` WHERE (`calendar_lines`.`user_id` = 14124 AND `calendar_lines`.date = '2010-05-18' AND `calendar_lines`.user_shop_id = 1) LIMIT 1
  CalendarLine Create (0.2ms)   INSERT INTO `calendar_lines` (`user_shop_id`, `user_id`, `date`, `spec`, `confirmed`, `amount`) VALUES(1, 14124, '2010-05-18', 'a', 5, 0.0)
  Fragment Create (0.2ms)   INSERT INTO `fragments` (`calendar_line_id`, `rel_type`, `rel_id`, `start_time`, `end_time`, `amount`, `breaks`, `color`, `description`) VALUES(2443990, 'a', 70, NULL, NULL, NULL, 0.0, NULL, NULL)
  SQL (34.2ms)   COMMIT
  Delayed::Backend::ActiveRecord::Job Columns (0.8ms)   SHOW FIELDS FROM `delayed_jobs`

ArgumentError (wrong number of arguments(1 for 0)):
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/site_ruby/1.9.1/psych/visitors/yaml_tree.rb:48:in `method'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/site_ruby/1.9.1/psych/visitors/yaml_tree.rb:48:in `accept'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/site_ruby/1.9.1/psych/visitors/yaml_tree.rb:36:in `<<'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/site_ruby/1.9.1/psych.rb:165:in `dump'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/site_ruby/1.9.1/psych/core_ext.rb:13:in `psych_to_yaml'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/syck/rubytypes.rb:88:in `to_yaml'
  vendor/plugins/delayed_job/lib/delayed/backend/base.rb:53:in `payload_object='
  config/initializers/extensions_rails.rb:23:in `create'
  vendor/plugins/delayed_job/lib/delayed/message_sending.rb:11:in `method_missing'
  app/models/calendar_line.rb:869:in `after_confirm'
  app/controllers/schedule/calendar_controller.rb:198:in `confirm_date'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:111:in `service'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/httpserver.rb:70:in `run'
  /home/vidmantas/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/webrick/server.rb:183:in `block in start_thread'

Rendered rescues/_trace (71.8ms)
Rendered rescues/_request_and_response (1.3ms)
Rendering rescues/layout (internal_server_error)

Sorry, I don't remember 100%, but I think it's needed to install libyaml-dev package and reinstall Ruby

Oh ok. Thanks! Looks like your's in an Ubuntu, mine is a RHEL box and already have libyaml and libyaml-devel packages installed.
The problem seems to be in delayed_job, this is the patch that fixes it https://github.com/pda/delayed_job/compare/v2.1.3...master