I use the following code in one of my snippets:

<% if @host.param_true? 'yum_update_post_build' %>

As of 1.9, this code is causing the template to fail with the following error:

There was an error rendering the provision-el7-corp template: The snippet 'yum_update' threw an error: undefined local variable or method `value' for #<Host::Managed:0x0000000bdd3730>

The following traceback is seen in the logs:

2015-09-24 06:56:24 [app] [I]   Rendered inline template (90.4ms)
2015-09-24 06:56:24 [app] [W] There was an error rendering the provision-el7-corp template:
 | ActionView::Template::Error: The snippet 'yum_update' threw an error: undefined local variable or method `value' for #<Host::Managed:0x0000000bdd3730>
 | /usr/share/foreman/lib/foreman/renderer.rb:76:in `rescue in snippet'
 | /usr/share/foreman/lib/foreman/renderer.rb:73:in `snippet'
 | (erb):78:in `render_safe'
 | /opt/rh/ruby193/root/usr/share/ruby/erb.rb:838:in `eval'
 | /opt/rh/ruby193/root/usr/share/ruby/erb.rb:838:in `result'
 | /usr/share/foreman/lib/foreman/renderer.rb:20:in `render_safe'
 | /usr/share/foreman/lib/foreman/renderer.rb:104:in `unattended_render'
 | inline template:1:in `_inline_template__4306414740314172163_94335360'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/template.rb:145:in `block in render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications.rb:125:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/template.rb:143:in `render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/template_renderer.rb:47:in `block (2 levels) in render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/abstract_renderer.rb:38:in `block in instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications.rb:123:in `block in instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications.rb:123:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/abstract_renderer.rb:38:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/template_renderer.rb:46:in `block in render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/template_renderer.rb:54:in `render_with_layout'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/template_renderer.rb:45:in `render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/template_renderer.rb:18:in `render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/renderer.rb:36:in `render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_view/renderer/renderer.rb:17:in `render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/rendering.rb:110:in `_render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/streaming.rb:225:in `_render_template'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/rendering.rb:103:in `render_to_body'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/renderers.rb:28:in `render_to_body'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/compatibility.rb:50:in `render_to_body'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/rendering.rb:88:in `render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/rendering.rb:16:in `render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:40:in `block (2 levels) in render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/core_ext/benchmark.rb:5:in `block in ms'
 | /opt/rh/ruby193/root/usr/share/ruby/benchmark.rb:295:in `realtime'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/core_ext/benchmark.rb:5:in `ms'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:40:in `block in render'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:83:in `cleanup_view_runtime'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/railties/controller_runtime.rb:24:in `cleanup_view_runtime'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:39:in `render'
 | /usr/share/foreman/app/controllers/unattended_controller.rb:222:in `safe_render'
 | /usr/share/foreman/app/controllers/unattended_controller.rb:79:in `render_template'
 | /usr/share/foreman/app/controllers/unattended_controller.rb:61:in `block (2 levels) in <class:UnattendedController>'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/base.rb:167:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/rendering.rb:10:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/callbacks.rb:18:in `block in process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:682:in `block (4 levels) in _run__832584820853669599__process_action__4083537450111310915__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in _conditional_callback_around_7551'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:326:in `around'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:310:in `_callback_around_2433'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_7551'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:626:in `block (3 levels) in _run__832584820853669599__process_action__4083537450111310915__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in _conditional_callback_around_7550'
 | /usr/share/foreman/app/controllers/concerns/application_shared.rb:13:in `set_timezone'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_7550'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:625:in `block (2 levels) in _run__832584820853669599__process_action__4083537450111310915__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in _conditional_callback_around_7549'
 | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:32:in `clear_thread'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_7549'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:448:in `block in _run__832584820853669599__process_action__4083537450111310915__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in _conditional_callback_around_7548'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:326:in `around'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:310:in `_callback_around_13'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_7548'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:414:in `_run__832584820853669599__process_action__4083537450111310915__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:405:in `__run_callback'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:81:in `run_callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/callbacks.rb:17:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/rescue.rb:29:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications.rb:123:in `block in instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/notifications.rb:123:in `instrument'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/instrumentation.rb:29:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/railties/controller_runtime.rb:18:in `process_action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/base.rb:121:in `process'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/rendering.rb:45:in `process'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal.rb:203:in `dispatch'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal.rb:246:in `block in action'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/routing/route_set.rb:73:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/routing/route_set.rb:36:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/journey-1.0.4/lib/journey/router.rb:68:in `block in call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/journey-1.0.4/lib/journey/router.rb:56:in `each'
 | /opt/rh/ruby193/root/usr/share/gems/gems/journey-1.0.4/lib/journey/router.rb:56:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/routing/route_set.rb:600:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/apipie-rails-0.2.6/lib/apipie/static_dispatcher.rb:65:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/apipie-rails-0.2.6/lib/apipie/extractor/recorder.rb:97:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/static.rb:62:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/apipie-rails-0.2.6/lib/apipie/middleware/checksum_in_headers.rb:27:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/etag.rb:23:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/conditionalget.rb:25:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/head.rb:14:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/params_parser.rb:21:in `call'
 | /usr/share/foreman/lib/middleware/catch_json_parse_errors.rb:9:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/flash.rb:242:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:205:in `context'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/session/abstract/id.rb:200:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/cookies.rb:339:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/query_cache.rb:64:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:405:in `_run__1467866470230691480__call__2723699945141609880__callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:405:in `__run_callback'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:81:in `run_callbacks'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.8/lib/rails/rack/logger.rb:26:in `call_app'
 | /opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.8/lib/rails/rack/logger.rb:16:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/request_id.rb:22:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/methodoverride.rb:21:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/runtime.rb:17:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/lock.rb:15:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_dispatch/middleware/static.rb:62:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-cache-1.2/lib/rack/cache/context.rb:136:in `forward'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-cache-1.2/lib/rack/cache/context.rb:245:in `fetch'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-cache-1.2/lib/rack/cache/context.rb:185:in `lookup'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-cache-1.2/lib/rack/cache/context.rb:66:in `call!'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-cache-1.2/lib/rack/cache/context.rb:51:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.8/lib/rails/engine.rb:479:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.8/lib/rails/application.rb:223:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/railties-3.2.8/lib/rails/railtie/configurable.rb:30:in `method_missing'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/builder.rb:134:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/urlmap.rb:64:in `block in call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `each'
 | /opt/rh/ruby193/root/usr/share/gems/gems/rack-1.4.1/lib/rack/urlmap.rb:49:in `call'
 | /usr/share/gems/gems/passenger-4.0.18/lib/phusion_passenger/rack/thread_handler_extension.rb:77:in `process_request'
 | /usr/share/gems/gems/passenger-4.0.18/lib/phusion_passenger/request_handler/thread_handler.rb:140:in `accept_and_process_next_request'
 | /usr/share/gems/gems/passenger-4.0.18/lib/phusion_passenger/request_handler/thread_handler.rb:108:in `main_loop'
 | /usr/share/gems/gems/passenger-4.0.18/lib/phusion_passenger/request_handler.rb:441:in `block (3 levels) in start_threads'
 | /opt/rh/ruby193/root/usr/share/gems/gems/logging-1.8.2/lib/logging/diagnostic_context.rb:323:in `call'
 | /opt/rh/ruby193/root/usr/share/gems/gems/logging-1.8.2/lib/logging/diagnostic_context.rb:323:in `block in create_with_logging_context'
2015-09-24 06:56:24 [app] [I]   Rendered text template (0.0ms)
2015-09-24 06:56:24 [app] [I] Completed 500 Internal Server Error in 405ms (Views: 0.7ms | ActiveRecord: 4.7ms)
2015-09-24 06:56:25 [app] [I]
 |