Issue #22267 has been reported by yahonda (Yasuo Honda). ---------------------------------------- Bug #22267: Active Support tests started failing on ruby master (bisected to #18194) https://bugs.ruby-lang.org/issues/22267 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-26T07:05:32Z master 346b261abe) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- On ruby-head, the Active Support (Rails) test suite fails with two Ractor-related errors (rails-nightly build 4651, https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eada-492d-954...). Rails CI failure. To reproduce on the Rails side, build ruby master, then in a rails/rails checkout run the two tests from activesupport/: ``` $ ruby -v ruby 4.1.0dev (2026-08-26T07:05:32Z master 346b261abe) +PRISM [x86_64-linux] $ bundle exec ruby -Ilib:test test/time_zone_test.rb -n test_formatted_offset_in_ractor #<Thread:...> terminated with exception (report_on_exception is true): lib/active_support/time_with_zone.rb:78:in 'ActiveSupport::TimeWithZone#period': undefined method 'period_for_utc' for nil (NoMethodError) from lib/active_support/time_with_zone.rb:139:in 'ActiveSupport::TimeWithZone#zone' from lib/active_support/time_with_zone.rb:59:in 'ActiveSupport::TimeWithZone#initialize' from lib/active_support/time_with_zone.rb:535:in 'ActiveSupport::TimeWithZone#marshal_load' 1) Error: TimeZoneTest#test_formatted_offset_in_ractor: Ractor::RemoteError: thrown by remote Ractor. lib/active_support/testing/ractors_assertions.rb:15:in 'Ractor#join' lib/active_support/testing/ractors_assertions.rb:15:in 'ActiveSupport::Testing::RactorsAssertions#on_ractor' test/time_zone_test.rb:895:in 'TimeZoneTest#test_formatted_offset_in_ractor' $ bundle exec ruby -Ilib:test test/notifications_test.rb -n test_record_and_set_subscriptions_when_using_a_regexp 1) Error: Notifications::NotificationSubscriptionTest#test_record_and_set_subscriptions_when_using_a_regexp: Ractor::Error: can not copy Hash object. lib/active_support/ractors.rb:117:in 'Ractor.make_shareable' lib/active_support/ractors.rb:117:in 'ActiveSupport::Ractors.make_shareable' lib/active_support/ractors.rb:79:in 'ActiveSupport::Ractors.try_make_shareable' lib/active_support/notifications.rb:359:in 'ActiveSupport::Notifications.record_subscriptions' lib/active_support/notifications.rb:314:in 'ActiveSupport::Notifications.subscribe' test/notifications_test.rb:604:in 'block in <class:NotificationSubscriptionTest>' ``` git bisect points at #18194 (Per-Ractor GC). Both reduce to Ractor copy and reproduce without Rails. Steps to reproduce (pure Ruby). (1) mirrors TimeZoneTest#test_formatted_offset_in_ractor — an object with a Time ivar (which now forces a Marshal fallback) whose marshal_load reconstructs from state only reachable in the main Ractor: ``` class Registry @zones = { "z" => Object.new } def self.find(name) = @zones.fetch(name) # reads a class-level ivar end class Wrapper def initialize(name) = (@name = name; @time = Time.now; @zone = Registry.find(name)) def marshal_dump = @name def marshal_load(name) = (@name = name; @time = Time.now; @zone = Registry.find(name)) end port = Ractor::Port.new Ractor.new(port, Wrapper.new("z")) { |p, o| p.send :ok }.join p port.receive ``` (2) mirrors Notifications...test_record_and_set_subscriptions_when_using_a_regexp — a Hash holding a Set and a shareable Proc: ``` require "set" Ractor.make_shareable({ s: Set.new([1, 2]), p: Ractor.shareable_proc {} }, copy: true) ``` Expected behavior. On Ruby 4.0.6 and before #18194 (50745e3e48): - (1) copies natively, marshal_load is not called, and prints :ok. - (2) succeeds. Actual behavior. On current master (346b261abe) and since #18194 (4f6c34eea6): (1): ``` #<Thread:...> terminated with exception (report_on_exception is true): -:3:in 'Registry.find': can not get unshareable values from instance variables of classes/modules from non-main Ractors (@zones from Registry) (Ractor::IsolationError) from -:8:in 'Wrapper#marshal_load' -:11:in 'Ractor#join': thrown by remote Ractor. (Ractor::RemoteError) from -:11:in '<main>' ``` marshal_load now runs in the receiver Ractor, where the object cannot reach main-Ractor state. In Active Support the same happens in TimeWithZone#marshal_load; there Time.find_zone rescues this and returns nil, so the Rails trace shows period_for_utc for nil instead. (2): ``` -:2:in 'Ractor.make_shareable': can not copy Hash object. (Ractor::Error) from -:2:in '<main>' -:2:in 'Ractor.make_shareable': no _dump_data is defined for class Proc (TypeError) from -:2:in '<main>' ``` -- https://bugs.ruby-lang.org/