Ignored_environments.yml inop: Failed to parse environment ignore file' error (NoMethodError): undefined method `respond_to' for Psych:Module

Problem:
Settings to ignore puppet classes and envs are not evaluated any more:
/usr/share/foreman/config/ignored_environments.yml config not working anymore and is ignored

See trace below. This file was working and pared since a long time; as per docs

Expected outcome:
Listed puppet classes are ignored

Foreman and Proxy versions:
3.15

Foreman and Proxy plugin versions:

Distribution and version:
EL9.6 (rocky)

Other relevant data:

:ignored:
  - common
:filters:
  - !ruby/regexp '/::params$/'
  - !ruby/regexp '/::base$/'
  - !ruby/regexp '/::install$/'
  - !ruby/regexp '/::service$/'
  - !ruby/regexp '/::config$/'
  - !ruby/regexp '/wget$/'
  - !ruby/regexp '/stdlib/'
  - !ruby/regexp '/acl$/'
  - !ruby/regexp '/iis$/'
  - !ruby/regexp '/concat/'
  - !ruby/regexp '/registry/'
  - !ruby/regexp '/inifile$/'
  - !ruby/regexp '/windows_services$/'
  - !ruby/regexp '/mblib$/'
  - !ruby/regexp '/homebrew/'
  - !ruby/regexp '/apt/'
  - !ruby/regexp '/chocolatey/'
  - !ruby/regexp '/^puppet_agent::/'
  - !ruby/regexp '/^nats::/'
  - !ruby/regexp '/^mcollective::/'
  - !ruby/regexp '/^mcollective_a/'
  - !ruby/regexp '/^mcollective_u/'

trace:

2025-08-01T10:42:32 [I|app|c586e3df] Backtrace for 'Failed to parse environment ignore file' error (NoMethodError): undefined method `respond_to' for Psych:Module
 c586e3df | Did you mean?  respond_to?
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb:234:in `load_ignored_file'
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb:246:in `ignored_file'
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb:220:in `ignored_environments'
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb:169:in `actual_environments'
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb:26:in `changes'
 c586e3df | /usr/share/gems/gems/foreman_puppet-9.0.0/app/controllers/concerns/foreman_puppet/environments_import.rb:12:in `import_environments'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/abstract_controller/base.rb:215:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/rendering.rb:165:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/abstract_controller/callbacks.rb:234:in `block in process_action'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:118:in `block in run_callbacks'
 c586e3df | /usr/share/foreman/app/controllers/concerns/foreman/controller/timezone.rb:10:in `set_timezone'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:127:in `block in run_callbacks'
 c586e3df | /usr/share/foreman/app/models/concerns/foreman/thread_session.rb:32:in `clear_thread'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:127:in `block in run_callbacks'
 c586e3df | /usr/share/foreman/app/controllers/concerns/foreman/controller/topbar_sweeper.rb:12:in `set_topbar_sweeper_controller'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:127:in `block in run_callbacks'
 c586e3df | /usr/share/gems/gems/audited-5.8.0/lib/audited/sweeper.rb:16:in `around'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:127:in `block in run_callbacks'
 c586e3df | /usr/share/gems/gems/audited-5.8.0/lib/audited/sweeper.rb:16:in `around'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:127:in `block in run_callbacks'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:138:in `run_callbacks'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/abstract_controller/callbacks.rb:233:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/rescue.rb:23:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/instrumentation.rb:67:in `block in process_action'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/notifications.rb:206:in `block in instrument'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/notifications.rb:206:in `instrument'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/instrumentation.rb:66:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal/params_wrapper.rb:259:in `process_action'
 c586e3df | /usr/share/gems/gems/activerecord-7.0.8.7/lib/active_record/railties/controller_runtime.rb:27:in `process_action'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/abstract_controller/base.rb:151:in `process'
 c586e3df | /usr/share/gems/gems/actionview-7.0.8.7/lib/action_view/rendering.rb:39:in `process'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal.rb:188:in `dispatch'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_controller/metal.rb:251:in `dispatch'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/route_set.rb:49:in `dispatch'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/route_set.rb:32:in `serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:50:in `block in serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:32:in `each'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:32:in `serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/route_set.rb:852:in `call'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/engine.rb:530:in `call'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/railtie.rb:226:in `public_send'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/railtie.rb:226:in `method_missing'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/mapper.rb:19:in `block in <class:Constraints>'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/mapper.rb:48:in `serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:50:in `block in serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:32:in `each'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/journey/router.rb:32:in `serve'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/routing/route_set.rb:852:in `call'
 c586e3df | /usr/share/gems/gems/apipie-dsl-2.6.2/lib/apipie_dsl/static_dispatcher.rb:67:in `call'
 c586e3df | /usr/share/gems/gems/apipie-rails-1.4.2/lib/apipie/static_dispatcher.rb:74:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/static.rb:23:in `call'
 c586e3df | /usr/share/foreman/lib/foreman/middleware/libvirt_connection_cleaner.rb:9:in `call'
 c586e3df | /usr/share/foreman/lib/foreman/middleware/telemetry.rb:10:in `call'
 c586e3df | /usr/share/gems/gems/apipie-rails-1.4.2/lib/apipie/middleware/checksum_in_headers.rb:27:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/tempfile_reaper.rb:15:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/etag.rb:27:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/conditional_get.rb:27:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/head.rb:12:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/http/permissions_policy.rb:38:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/http/content_security_policy.rb:39:in `call'
 c586e3df | /usr/share/foreman/lib/foreman/middleware/logging_context_session.rb:22:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/session/abstract/id.rb:266:in `context'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/session/abstract/id.rb:260:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/cookies.rb:704:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/callbacks.rb:99:in `run_callbacks'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/callbacks.rb:26:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/debug_exceptions.rb:28:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/show_exceptions.rb:29:in `call'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/rack/logger.rb:40:in `call_app'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/rack/logger.rb:27:in `call'
 c586e3df | /usr/share/gems/gems/sprockets-rails-3.5.2/lib/sprockets/rails/quiet_assets.rb:17:in `call'
 c586e3df | /usr/share/foreman/lib/foreman/middleware/logging_context_request.rb:11:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/remote_ip.rb:93:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/request_id.rb:26:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/method_override.rb:24:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/runtime.rb:22:in `call'
 c586e3df | /usr/share/gems/gems/activesupport-7.0.8.7/lib/active_support/cache/strategy/local_cache_middleware.rb:29:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/executor.rb:14:in `call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/sendfile.rb:110:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/ssl.rb:77:in `call'
 c586e3df | /usr/share/gems/gems/actionpack-7.0.8.7/lib/action_dispatch/middleware/host_authorization.rb:131:in `call'
 c586e3df | /usr/share/gems/gems/secure_headers-7.1.0/lib/secure_headers/middleware.rb:11:in `call'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/engine.rb:530:in `call'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/railtie.rb:226:in `public_send'
 c586e3df | /usr/share/gems/gems/railties-7.0.8.7/lib/rails/railtie.rb:226:in `method_missing'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/urlmap.rb:74:in `block in call'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/urlmap.rb:58:in `each'
 c586e3df | /usr/share/gems/gems/rack-2.2.4/lib/rack/urlmap.rb:58:in `call'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/configuration.rb:279:in `call'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/request.rb:99:in `block in handle_request'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/thread_pool.rb:390:in `with_force_shutdown'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/request.rb:98:in `handle_request'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/server.rb:472:in `process_client'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/server.rb:254:in `block in run'
 c586e3df | /usr/share/gems/gems/puma-6.6.0/lib/puma/thread_pool.rb:167:in `block in spawn_thread'
 c586e3df | /usr/share/gems/gems/logging-2.4.0/lib/logging/diagnostic_context.rb:474:in `block in create_with_logging_context'

Well, the below trivial patch will fix it for now. Don’t forget to restart Foreman - and note this is the updated puppet plugin 9.0.0:

--- puppet_class_importer.rb    2025-08-01 11:08:24.043282493 +0200
+++ /usr/share/gems/gems/foreman_puppet-9.0.0/app/services/foreman_puppet/puppet_class_importer.rb      2025-08-01 11:08:36.617138012 +0200
@@ -231,7 +231,7 @@
     def load_ignored_file
       if File.exist?(ignored_file_path)
         # Ruby 3+
-        if YAML.respond_to(:safe_load_file)
+        if YAML.respond_to?(:safe_load_file)
           YAML.safe_load_file(ignored_file_path, permitted_classes: [Symbol, Regexp])
         else
           # NOTE: Once we drop Ruby 2.7 support, you can drop the load_file call.

PR submitted, FWIW :wink: