Doesn't work with Rails_admin

[davidwparker]

Full trace:

Type Mongoid::TagsArentHard::Tags for field :tags in MyModel not supported

rails_admin (0.5.0) lib/rails_admin/adapters/mongoid.rb:310:in `type_lookup'
rails_admin (0.5.0) lib/rails_admin/adapters/mongoid.rb:92:in `block in properties'
rails_admin (0.5.0) lib/rails_admin/adapters/mongoid.rb:85:in `each'
rails_admin (0.5.0) lib/rails_admin/adapters/mongoid.rb:85:in `map'
rails_admin (0.5.0) lib/rails_admin/adapters/mongoid.rb:85:in `properties'
rails_admin (0.5.0) lib/rails_admin/config/actions/dashboard.rb:29:in `block (3 levels) in <class:Dashboard>'
rails_admin (0.5.0) lib/rails_admin/config/actions/dashboard.rb:24:in `each'
rails_admin (0.5.0) lib/rails_admin/config/actions/dashboard.rb:24:in `block (2 levels) in <class:Dashboard>'
(eval):8:in `instance_eval'
(eval):8:in `dashboard'
actionpack (4.0.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.0) lib/active_support/callbacks.rb:443:in `_run__2739951418677313808__process_action__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.0) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.0) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
actionpack (4.0.0) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.0) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.0) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/railtie/configurable.rb:30:in `method_missing'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.0) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.0) lib/action_dispatch/routing/route_set.rb:655:in `call'
rack-pjax (0.7.0) lib/rack/pjax.rb:12:in `call'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bundler/gems/mongoid-d52c33bce36a/lib/rack/mongoid/middleware/identity_map.rb:34:in `block in call'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bundler/gems/mongoid-d52c33bce36a/lib/mongoid/unit_of_work.rb:39:in `unit_of_work'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bundler/gems/mongoid-d52c33bce36a/lib/rack/mongoid/middleware/identity_map.rb:34:in `call'
warden (1.2.1) lib/warden/manager.rb:35:in `block in call'
warden (1.2.1) lib/warden/manager.rb:34:in `catch'
warden (1.2.1) 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:25:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
remotipart (1.1.1) lib/remotipart/middleware.rb:25:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.0) 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 (4.0.0) lib/action_dispatch/middleware/cookies.rb:486:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__226034610281748181__call__callbacks'
activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
actionpack (4.0.0) 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 (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
railties (4.0.0) lib/rails/engine.rb:511:in `call'
railties (4.0.0) lib/rails/application.rb:97:in `call'
railties (4.0.0) lib/rails/railtie/configurable.rb:30:in `method_missing'
rack (1.5.2) lib/rack/lint.rb:49:in `_call'
rack (1.5.2) lib/rack/lint.rb:37:in `call'
rack (1.5.2) lib/rack/showexceptions.rb:24:in `call'
rack (1.5.2) lib/rack/commonlogger.rb:33:in `call'
rack (1.5.2) lib/rack/chunked.rb:43:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
unicorn (4.6.3) lib/unicorn/http_server.rb:552:in `process_client'
unicorn (4.6.3) lib/unicorn/http_server.rb:632:in `worker_loop'
unicorn (4.6.3) lib/unicorn/http_server.rb:500:in `spawn_missing_workers'
unicorn (4.6.3) lib/unicorn/http_server.rb:142:in `start'
unicorn (4.6.3) bin/unicorn:126:in `<top (required)>'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bin/unicorn:23:in `load'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bin/unicorn:23:in `<main>'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bin/ruby_noexec_wrapper:14:in `eval'
/Users/dparker/.rvm/gems/ruby-2.0.0-p247/bin/ruby_noexec_wrapper:14:in `<main>'

Important Gems:

ruby '2.0.0'

gem 'rails', '4.0.0'
gem 'mongoid', git: 'https://github.com/mongoid/mongoid.git'