Relation to yaml

gistfile1.sh

>> {a: User.where(initials: 'TT')}.to_yaml
  User Load (0.4ms)  SELECT "users".* FROM "users" WHERE "users"."initials" = 'TT'
ArgumentError: wrong number of arguments (2 for 1)
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/arel-3.0.2/lib/arel/expressions.rb:3:in `count'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:222:in `visit_String'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:134:in `block in visit_Struct'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:132:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:132:in `visit_Struct'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:294:in `block in visit_Array'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:294:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:294:in `visit_Array'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:377:in `block in dump_ivars'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:375:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:375:in `dump_ivars'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:124:in `visit_Object'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
... 7 levels...
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:375:in `dump_ivars'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:124:in `visit_Object'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:275:in `block in visit_Hash'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:273:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:273:in `visit_Hash'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:102:in `accept'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/visitors/yaml_tree.rb:66:in `push'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych.rb:189:in `dump'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/psych/core_ext.rb:14:in `psych_to_yaml'
  from (irb):9
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands/console.rb:47:in `start'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands/console.rb:8:in `start'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:41:in `<top (required)>'
  from script/rails:6:in `require'
  from script/rails:6:in `<main>'


>> {a: User.where(initials: 'TT').all}.to_yaml
  User Load (0.4ms)  SELECT "users".* FROM "users" WHERE "users"."initials" = 'TT'
=> "---\n:a:\n- !ruby/ActiveRecord:User\n.....blah blah great success"

>> YAML::ENGINE.yamler = 'syck'
=> "syck"

>> {a: User.where(initials: 'TT')}.to_yaml
  User Load (0.4ms)  SELECT "users".* FROM "users" WHERE "users"."initials" = 'TT'
NoMethodError: undefined method `tag=' for #<Hash:0x007ffc0589fb80>
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/delayed_job-3.0.1/lib/delayed/psych_ext.rb:6:in `encode_with'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/activerecord-3.2.2/lib/active_record/base.rb:655:in `to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:115:in `node_export'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:115:in `add'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:115:in `block (3 levels) in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:114:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:114:in `block (2 levels) in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:113:in `seq'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:113:in `block in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `call'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `emit'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `quick_emit'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:112:in `to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/activerecord-3.2.2/lib/active_record/relation/delegation.rb:6:in `to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:44:in `node_export'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:44:in `add'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:44:in `block (3 levels) in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:43:in `each'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:43:in `block (2 levels) in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:42:in `map'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:42:in `block in to_yaml'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `call'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `emit'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck.rb:401:in `quick_emit'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/1.9.1/syck/rubytypes.rb:41:in `to_yaml'
  from (irb):12
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands/console.rb:47:in `start'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands/console.rb:8:in `start'
  from /Users/tadas/.rbenv/versions/1.9.3-p0-perf/lib/ruby/gems/1.9.1/gems/railties-3.2.2/lib/rails/commands.rb:41:in `<top (required)>'