Overloading to_json with JSON gem installed causing error

I installed the JSON gem because I wanted the JSON parser.

Before installing the JSON gem, overloading worked fine. Before I
remove it, I’d like to see if anyone has an idea of what is going on.
It’s the only JSON parser I’m aware of, so it would be a bummer if it
didn’t work.

After installing, if I overload the to_json method in the class, it
gives me the following error:

wrong number of arguments (2 for 0)

RAILS_ROOT: script/…/config/…
Application Trace | Framework Trace | Full Trace

/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:in
to_json' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:injson_transform’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:621:in
json_transform' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:606:in
json_check_circular' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
app/controllers/item_controller.rb:92:in `list’

/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:in
to_json' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:injson_transform’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:621:in
json_transform' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:606:in
json_check_circular' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/base.rb:1095:in perform_action_without_filters' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:632:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:634:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:638:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:438:in call' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:637:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:638:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:438:incall’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:637:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:619:inperform_action_without_benchmark’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/benchmarking.rb:66:in
perform_action_without_rescue' /usr/local/lib/ruby/1.8/benchmark.rb:293:inmeasure’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/benchmarking.rb:66:in
perform_action_without_rescue' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/rescue.rb:83:inperform_action’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/base.rb:430:in process_without_filters' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:624:inprocess_without_session_management_support’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/session_management.rb:114:in process' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/base.rb:330:inprocess’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/dispatcher.rb:41:in
dispatch' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb: 113:inhandle_dispatch’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb:
79:in service' /usr/local/lib/ruby/1.8/webrick/httpserver.rb:104:inservice’
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:65:in run' /usr/local/lib/ruby/1.8/webrick/server.rb:173:instart_thread’
/usr/local/lib/ruby/1.8/webrick/server.rb:162:in start_thread' /usr/local/lib/ruby/1.8/webrick/server.rb:95:instart’
/usr/local/lib/ruby/1.8/webrick/server.rb:92:in start' /usr/local/lib/ruby/1.8/webrick/server.rb:23:instart’
/usr/local/lib/ruby/1.8/webrick/server.rb:82:in start' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb: 63:indispatch’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/commands/servers/
webrick.rb:59
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
require' /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/ active_support/dependencies.rb:495:inrequire’
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/
active_support/dependencies.rb:342:in new_constants_in' /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/ active_support/dependencies.rb:495:inrequire’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/commands/server.rb:
39
/usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in
`require’
script/server:3

/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:in
to_json' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:622:injson_transform’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:621:in
json_transform' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
/usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:606:in
json_check_circular' /usr/local/lib/ruby/gems/1.8/gems/json-0.4.3/lib/json.rb:595:into_json’
app/controllers/item_controller.rb:92:in list' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/base.rb:1095:inperform_action_without_filters’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:632:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:634:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:638:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:438:incall’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:637:in call_filter' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:638:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:438:in call' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/filters.rb:637:incall_filter’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:619:in perform_action_without_benchmark' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/benchmarking.rb:66:inperform_action_without_rescue’
/usr/local/lib/ruby/1.8/benchmark.rb:293:in measure' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/benchmarking.rb:66:inperform_action_without_rescue’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/rescue.rb:83:in perform_action' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/base.rb:430:inprocess_without_filters’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/filters.rb:624:in
process_without_session_management_support' /usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/ action_controller/session_management.rb:114:inprocess’
/usr/local/lib/ruby/gems/1.8/gems/actionpack-1.13.2/lib/
action_controller/base.rb:330:in process' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/dispatcher.rb:41:indispatch’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb:
113:in handle_dispatch' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb: 79:inservice’
/usr/local/lib/ruby/1.8/webrick/httpserver.rb:104:in service' /usr/local/lib/ruby/1.8/webrick/httpserver.rb:65:inrun’
/usr/local/lib/ruby/1.8/webrick/server.rb:173:in start_thread' /usr/local/lib/ruby/1.8/webrick/server.rb:162:instart_thread’
/usr/local/lib/ruby/1.8/webrick/server.rb:95:in start' /usr/local/lib/ruby/1.8/webrick/server.rb:92:instart’
/usr/local/lib/ruby/1.8/webrick/server.rb:23:in start' /usr/local/lib/ruby/1.8/webrick/server.rb:82:instart’
/usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/webrick_server.rb:
63:in dispatch' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/commands/servers/ webrick.rb:59 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:inrequire’
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/
active_support/dependencies.rb:495:in require' /usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/ active_support/dependencies.rb:342:innew_constants_in’
/usr/local/lib/ruby/gems/1.8/gems/activesupport-1.4.1/lib/
active_support/dependencies.rb:495:in require' /usr/local/lib/ruby/gems/1.8/gems/rails-1.2.2/lib/commands/server.rb: 39 /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:inrequire’
script/server:3