NoMethodError (private method `select' called for #<String:0x00000006f2ef08>):

[marine44]

Any ideas why I get this when receiving a mailgun "Send A Sample POST" test email:

I, [2014-05-28T11:07:07.182971 #1296]  INFO -- : Completed 500 Internal Server Error in 3ms
F, [2014-05-28T11:07:07.189249 #1296] FATAL -- : 
NoMethodError (private method `select' called for #<String:0x00000006f2ef08>):
  griddler (0.6.4) lib/griddler/adapters/mailgun_adapter.rb:42:in `extract_header_cc'
  griddler (0.6.4) lib/griddler/adapters/mailgun_adapter.rb:36:in `ccs'
  griddler (0.6.4) lib/griddler/adapters/mailgun_adapter.rb:16:in `normalize_params'
  griddler (0.6.4) lib/griddler/adapters/mailgun_adapter.rb:10:in `normalize_params'
  griddler (0.6.4) app/controllers/griddler/emails_controller.rb:12:in `normalized_params'
  griddler (0.6.4) app/controllers/griddler/emails_controller.rb:3:in `create'
  actionpack (4.0.3) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
  actionpack (4.0.3) lib/abstract_controller/base.rb:189:in `process_action'
  actionpack (4.0.3) lib/action_controller/metal/rendering.rb:10:in `process_action'
  actionpack (4.0.3) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
  activesupport (4.0.3) lib/active_support/callbacks.rb:423:in `_run__16735415116720946__process_action__callbacks'
  activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
  actionpack (4.0.3) lib/abstract_controller/callbacks.rb:17:in `process_action'
  actionpack (4.0.3) lib/action_controller/metal/rescue.rb:29:in `process_action'
  actionpack (4.0.3) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
  activesupport (4.0.3) lib/active_support/notifications.rb:159:in `block in instrument'
  activesupport (4.0.3) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
  activesupport (4.0.3) lib/active_support/notifications.rb:159:in `instrument'
  actionpack (4.0.3) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
  actionpack (4.0.3) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
  activerecord (4.0.3) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
  actionpack (4.0.3) lib/abstract_controller/base.rb:136:in `process'
  actionpack (4.0.3) lib/abstract_controller/rendering.rb:44:in `process'
  actionpack (4.0.3) lib/action_controller/metal.rb:195:in `dispatch'
  actionpack (4.0.3) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
  actionpack (4.0.3) lib/action_controller/metal.rb:231:in `block in action'
  actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:80:in `call'
  actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
  actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:48:in `call'
  actionpack (4.0.3) lib/action_dispatch/journey/router.rb:71:in `block in call'
  actionpack (4.0.3) lib/action_dispatch/journey/router.rb:59:in `each'
  actionpack (4.0.3) lib/action_dispatch/journey/router.rb:59:in `call'
  actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:680:in `call'
  newrelic_rpm (3.8.1.221) lib/new_relic/rack/error_collector.rb:55:in `call'
  newrelic_rpm (3.8.1.221) lib/new_relic/rack/agent_hooks.rb:32:in `call'
  newrelic_rpm (3.8.1.221) lib/new_relic/rack/browser_monitoring.rb:27:in `call'
  warden (1.2.3) lib/warden/manager.rb:35:in `block in call'
  warden (1.2.3) lib/warden/manager.rb:34:in `catch'
  warden (1.2.3) lib/warden/manager.rb:34:in `call'
  rack (1.5.2) lib/rack/etag.rb:23:in `call'
  rack (1.5.2) lib/rack/conditionalget.rb:35:in `call'
  rack (1.5.2) lib/rack/head.rb:11:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/flash.rb:241:in `call'
  rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
  rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/cookies.rb:486:in `call'
  activerecord (4.0.3) lib/active_record/query_cache.rb:36:in `call'
  activerecord (4.0.3) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
  activesupport (4.0.3) lib/active_support/callbacks.rb:373:in `_run__3385064544836038165__call__callbacks'
  activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
  actionpack (4.0.3) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.0.3) lib/rails/rack/logger.rb:38:in `call_app'
  railties (4.0.3) lib/rails/rack/logger.rb:20:in `block in call'
  activesupport (4.0.3) lib/active_support/tagged_logging.rb:67:in `block in tagged'
  activesupport (4.0.3) lib/active_support/tagged_logging.rb:25:in `tagged'
  activesupport (4.0.3) lib/active_support/tagged_logging.rb:67:in `tagged'
  railties (4.0.3) lib/rails/rack/logger.rb:20:in `call'
  actionpack (4.0.3) lib/action_dispatch/middleware/request_id.rb:21:in `call'
  rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
  rack (1.5.2) lib/rack/runtime.rb:17:in `call'
  activesupport (4.0.3) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
  rack (1.5.2) lib/rack/sendfile.rb:112:in `call'
  railties (4.0.3) lib/rails/engine.rb:511:in `call'
  railties (4.0.3) lib/rails/application.rb:97:in `call'
  unicorn (4.8.3) lib/unicorn/http_server.rb:576:in `process_client'
  unicorn (4.8.3) lib/unicorn/http_server.rb:670:in `worker_loop'
  unicorn (4.8.3) lib/unicorn/http_server.rb:525:in `spawn_missing_workers'
  unicorn (4.8.3) lib/unicorn/http_server.rb:140:in `start'
  unicorn (4.8.3) bin/unicorn:126:in `<top (required)>'

[marine44]

Duplicate of #122