[ruby-core:126497] [Ruby Bug#22263] Subject: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to 98f0921f2b)
Issue #22263 has been reported by yahonda (Yasuo Honda). ---------------------------------------- Bug #22263: Subject: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to 98f0921f2b) https://bugs.ruby-lang.org/issues/22263 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` 98f0921f2b06bcc6435fe96a99da3a857ac10477 introduces this behavior. ``` -- https://bugs.ruby-lang.org/
Issue #22263 has been updated by yahonda (Yasuo Honda). Correction on the bisect result. 98f0921f2b is where the forked RailtieTest children start to crash (SIGSEGV or ArgumentError), not where this NoMethodError starts. Bisecting for the NoMethodError itself, with the same bin/test command, gives: c59c4d717a2e687972341eab1574196e97d7d7be is the first bad commit Fix stale super cache on prepend after include From c59c4d717a on, the five RailtieTest children raise the NoMethodError in every run; at its parent e1fcca5c11 they crash instead. Still reproduces on master 89699e814e (2026-08-25). ---------------------------------------- Bug #22263: Subject: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to 98f0921f2b) https://bugs.ruby-lang.org/issues/22263#change-118660 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` 98f0921f2b06bcc6435fe96a99da3a857ac10477 introduces this behavior. ``` -- https://bugs.ruby-lang.org/
Issue #22263 has been updated by yahonda (Yasuo Honda). Subject changed from Subject: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to 98f0921f2b) to NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to c59c4d717a)
98f0921f2b06bcc6435fe96a99da3a857ac10477 introduces this behavior.
It is not ---------------------------------------- Bug #22263: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to c59c4d717a) https://bugs.ruby-lang.org/issues/22263#change-118661 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` 98f0921f2b06bcc6435fe96a99da3a857ac10477 introduces this behavior. ``` -- https://bugs.ruby-lang.org/
Issue #22263 has been updated by luke-gru (Luke Gruber). I have a reproduction showing the issue: ```ruby module M def foo print "M#foo(orig)" end end class C; include M; end M.prepend(Module.new do def foo print "P#foo(" super print ")" end end) C.new.foo # prime the super cache through the backfilled origin iclass puts puts "after primed cache" module M # zeitwerk wraps `require` with an alias alias_method :old_foo, :foo # captures the *prepended* P#foo instead of original M#foo def foo print "M#foo(" old_foo print ")" end end puts C.new.foo ``` Before c59c4d717a2e687972341eab1574196e97d7d7be, we get: ``` P#foo(M#foo(orig)) after primed cache P#foo(M#foo(orig)) // clearly wrong, the super cache in P#foo was never cleared so it didn't do a new lookup ``` After c59c4d717a2e687972341eab1574196e97d7d7be: ``` P#foo(M#foo(orig)) after primed cache P#foo(M#foo(P#foo(../ruby/test.rb:10:in 'foo': super: no superclass method 'foo' for an instance of C (NoMethodError) from ../ruby/test.rb:21:in 'M#foo' from ../ruby/test.rb:10:in 'foo' from ../ruby/test.rb:25:in '<main>' ``` Now instead of ignoring the new M#foo, it does a new lookup. However, because the alias in M#foo captured P#foo instead of M's original M#foo, we get an error. This is confusing behavior to me, and I would expect the lookup from M#foo to not go through P, as P shouldn't be an ancestor of M. However, I'm not sure it is a bug as this behavior may be intentional. With the way it currently works though, Module#prepend doesn't play well with aliasing when you alias from the module you prepended to. I'll work around this by not prepending the RactorRequire module to Kernel when we create a Ractor, as this doesn't interact well with Zeitwerk and Rubygems that alias `require`. @jeremyevans0 is this intentional or a bug? ---------------------------------------- Bug #22263: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to c59c4d717a) https://bugs.ruby-lang.org/issues/22263#change-118666 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` c59c4d717a2e687972341eab1574196e97d7d7be introduces this behavior. ``` -- https://bugs.ruby-lang.org/
Issue #22263 has been updated by jeremyevans0 (Jeremy Evans). luke-gru (Luke Gruber) wrote in #note-4:
[@jeremyevans0 (Jeremy Evans)](/users/1604) is this intentional or a bug?
This is general question of how aliased methods should work with prepend. Currently, we allow a class to alias a method in a module prepended to it: ```ruby module M def m = 1 end class C prepend M alias m2 m end C.new.m2 # => 1 ``` I think this is a design mistake. I think that conceptually, you should only be able to alias ancestor methods (same position or later in the lookup chain), and this allows aliasing a descendant method (earlier in the lookup chain). The ancestor chain in this case (in order of method lookup): ``` C.new.singleton_class M C Object Kernel BasicObject ``` I think in this case, `C` should only be allowed to alias methods of `C`, `Object`, `Kernel`, and `BasicObject`. I think the `alias m2 m` in the above example should be changed to raise `NameError`. ---------------------------------------- Bug #22263: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to c59c4d717a) https://bugs.ruby-lang.org/issues/22263#change-118668 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` c59c4d717a2e687972341eab1574196e97d7d7be introduces this behavior. ``` -- https://bugs.ruby-lang.org/
Issue #22263 has been updated by eightbitraptor (Matt V-H). I've just encountered this issue with the following repro: ``` Ractor.new { 1 }.value Kernel.module_eval { alias old_require require } old_require 'tempfile' ``` Thanks @luke-gru for pointing this ticket out to me. I ended up [patching it](https://github.com/eightbitraptor/ruby/commit/7cafd864c7b6bdb9e7cc7415e49631...) to match the existing semantics by making `super` start from after the prepended module rather than after the alias, but it sounds to me that @jeremyevans0 doesn't think that's the current semantics are correct. If we decide that this is a design mistake and change it for Ruby 4.1 what does the blast radius look like? How many gems and other projects are likely to be affected? Is this something that we want to patch now, but deprecate this release and fix properly for 4.2? ---------------------------------------- Bug #22263: NoMethodError: super: no superclass method 'require' for main — raised in a forked child process after a Ractor has exited in the parent (bisected to c59c4d717a) https://bugs.ruby-lang.org/issues/22263#change-118725 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 4.1.0dev (2026-08-25T14:03:04Z master 17026737cc) +PRISM [x86_64-linux] * Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ### 1. First occurrence in Rails CI https://buildkite.com/rails/rails-nightly/builds/4651#01a016ac-eaf9-4a71-9fb... (job "activemodel (master-debug)", 2026-08-18, ruby 4.1.0dev (2026-08-18T13:12:35Z master 6b719acc57) +PRISM [x86_64-linux]) Two Active Model tests ran a short-lived Ractor in the test process. A few seconds later, `RailtieTest` forked child processes (Active Support's fork-based test isolation), and the children failed while booting a Rails application. ### 2. Steps to reproduce A Rails checkout is required. Verified with Rails main 0f36bbf72c and the `rubylang/ruby:master` Docker image (ruby 4.1.0dev (2026-08-25T07:50:12Z master 753ace46fe)); it reproduces every run. ``` $ git clone https://github.com/rails/rails && cd rails && bundle install $ cd activemodel $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb ``` ### 3. Expected behavior The forked child behaves like its parent: the Rails application boots and the child exits with status 0 (`child: #<Process::Status: pid NNN exit 0>`). The test pair reports 0 errors. ### 4. Actual behavior The forked child raises an exception during `require` and exits with status 1; the parent process is unaffected: ``` $ bundle exec ruby -w -Ilib:test bin/test test/cases/naming_test.rb test/cases/railtie_test.rb Source locally installed gems is ignoring #<Bundler::StubSpecification name=psych version=5.5.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=prism version=1.9.0 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.8.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=io-console version=0.9.2 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=erb version=6.0.7 platform=ruby> because it is missing extensions Source locally installed gems is ignoring #<Bundler::StubSpecification name=date version=3.5.1 platform=ruby> because it is missing extensions Run options: --seed 20598 # Running: ............................................................E Error: RailtieTest#test_i18n_customize_full_message_defaults_to_false: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:36 E Error: RailtieTest#test_secure_password_min_cost_is_false_in_the_development_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:22 E Error: RailtieTest#test_i18n_customize_full_message_can_be_disabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:42 E Error: RailtieTest#test_secure_password_min_cost_is_true_in_the_test_environment: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:29 E Error: RailtieTest#test_i18n_customize_full_message_can_be_enabled: NoMethodError: super: no superclass method 'require' for main /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'require' /home/yahonda/.local/share/mise/installs/ruby/trunk/lib/ruby/gems/4.1.0+4/gems/zeitwerk-2.8.3/lib/zeitwerk/core_ext/kernel.rb:34:in 'Kernel#require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'require' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/application.rb:484:in 'Rails::Application#config' /home/yahonda/src/github.com/rails/rails/railties/lib/rails/railtie.rb:148:in 'Rails::Railtie.config' test/cases/railtie_test.rb:16:in 'block in RailtieTest#setup' test/cases/railtie_test.rb:15:in 'Class#initialize' test/cases/railtie_test.rb:15:in 'Class#new' test/cases/railtie_test.rb:15:in 'RailtieTest#setup' bin/test test/cases/railtie_test.rb:49 Finished in 0.088916s, 731.0243 runs/s, 820.9965 assertions/s. 65 runs, 73 assertions, 0 failures, 5 errors, 0 skips $ ``` ### 5. Bisect result ``` c59c4d717a2e687972341eab1574196e97d7d7be introduces this behavior. ``` -- https://bugs.ruby-lang.org/
participants (4)
-
eightbitraptor (Matt V-H) -
jeremyevans0 (Jeremy Evans)
-
luke-gru (Luke Gruber)
-
yahonda (Yasuo Honda)