April 2026 - ruby-core - ml.ruby-lang.org

[ruby-core:124270] [Ruby Bug#21787] `IO::Buffer` buffer overf
by nobu (Nobuyoshi Nakada) 04 Apr '26

04 Apr '26

Issue #21787 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21787: `IO::Buffer` buffer overf https://bugs.ruby-lang.org/issues/21787 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- -- https://bugs.ruby-lang.org/

3 3

[ruby-core:124594] [Ruby Bug#21844] Inconsistent ArgumentError message for Data::define.new
by jnchito (Junichi Ito) 04 Apr '26

04 Apr '26

Issue #21844 has been reported by jnchito (Junichi Ito). ---------------------------------------- Bug #21844: Inconsistent ArgumentError message for Data::define.new https://bugs.ruby-lang.org/issues/21844 * Author: jnchito (Junichi Ito) * Status: Open * ruby -v: ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [arm64-darwin25] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- The code below shows `Data::define.new` treats symbol and string keys equivalently: ``` ruby C = Data.define(:a, :b) C.new(a: 1, b: 1) #=> #<data C a=1, b=1> C.new('a' => 1, 'b' => 1) #=> #<data C a=1, b=1> ``` But it acts differently when detecting missing keywords: ```ruby C.new(a: 1) #=> 'Data#initialize': missing keyword: :b (ArgumentError) C.new('a' => 1) #=> 'Data#initialize': missing keywords: :a, :b (ArgumentError) ``` I feel it should work like this: ```ruby C.new('a' => 1) #=> 'Data#initialize': missing keyword: :b (ArgumentError) ``` I created a PR to fix it: https://github.com/ruby/ruby/pull/15910 -- https://bugs.ruby-lang.org/

6 12

[ruby-core:124655] [Ruby Bug#21856] Nokogiri performance degradation since Ruby 4.0
by ahorek 04 Apr '26

04 Apr '26

Issue #21856 has been reported by ahorek (Pavel Rosický). ---------------------------------------- Bug #21856: Nokogiri performance degradation since Ruby 4.0 https://bugs.ruby-lang.org/issues/21856 * Author: ahorek (Pavel Rosický) * Status: Open * ruby -v: ruby 4.1.0dev (2026-01-31T09:41:30Z master 7ef8c470d2) +PRISM [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- Loofah sanitization is noticeably slower ``` Ruby: 3.4.8 Loofah: 2.25.0 Nokogiri: 1.19.0 Iterations: 100000 user system total real Loofah.fragment + scrub!(:prune) 26.091872 0.000000 26.091872 ( 25.110925) Loofah.scrub_fragment(:prune) 25.913185 0.010392 25.923577 ( 24.948464) Nokogiri HTML parse only 3.852690 0.000000 3.852690 ( 3.705930) Ruby: 4.0.0 & 4.0.1 Loofah: 2.25.0 Nokogiri: 1.19.0 Iterations: 100000 user system total real Loofah.fragment + scrub!(:prune) 38.094207 0.041753 38.135960 ( 36.669463) Loofah.scrub_fragment(:prune) 40.168795 0.000045 40.168840 ( 38.561806) Nokogiri HTML parse only 4.012936 0.052024 4.064960 ( 3.913272) Ruby: 4.1.0 (ruby 4.1.0dev (2026-01-31T09:41:30Z master 7ef8c470d2) +PRISM [x86_64-linux]) Loofah: 2.25.0 Nokogiri: 1.19.0 Iterations: 100000 user system total real Loofah.fragment + scrub!(:prune) 39.004228 0.000000 39.004228 ( 37.694873) Loofah.scrub_fragment(:prune) 39.043199 0.031284 39.074483 ( 37.182785) Nokogiri HTML parse only 3.889100 0.010427 3.899527 ( 3.741622) ``` Originally reported https://www.redmine.org/issues/43737 ---Files-------------------------------- benchmark.rb (1002 Bytes) -- https://bugs.ruby-lang.org/

7 12

[ruby-core:125028] [Ruby Bug#21954] NoMethodError instead of Gem::LoadError on gem activation problem in Ruby 4.0.2
by jeremyevans0 (Jeremy Evans) 04 Apr '26

04 Apr '26

Issue #21954 has been reported by jeremyevans0 (Jeremy Evans). ---------------------------------------- Bug #21954: NoMethodError instead of Gem::LoadError on gem activation problem in Ruby 4.0.2 https://bugs.ruby-lang.org/issues/21954 * Author: jeremyevans0 (Jeremy Evans) * Status: Open * ruby -v: ruby 4.0.2 (2026-03-17 revision d3da9fec82) +PRISM [x86_64-linux] * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: DONTNEED, 4.0: REQUIRED ---------------------------------------- I'm seeing a regression in Ruby 4.0.2 when there is a gem activation problem. Install two versions of a gem, where one version has a file the other doesn't. One example here is rack: ``` $ gem install rack --version '< 3' $ gem install rack ``` Force activation of the version that doesn't have the file, and then require the file and rescue `LoadError`: ```ruby gem 'rack', '< 3' begin require 'rack/headers' rescue LoadError end ``` In previous versions of Ruby, the `Gem::LoadError` would be correctly rescued, and you would get no output. In Ruby 4.0.2, you get a `NoMethodError` raised: ``` /usr/local/lib/ruby/4.0/rubygems.rb:196:in 'Gem.try_activate': undefined method 'name' for nil (NoMethodError) spec ||= Gem::Specification.find_by_name(spec.name) ^^^^^ from /home/jeremy/gem-activate-problem.rb:4:in 'Kernel#require' from /home/jeremy/gem-activate-problem.rb:4:in '<main>' /usr/local/lib/ruby/4.0/rubygems/specification.rb:2170:in 'Gem::Specification#check_version_conflict': can't activate rack-3.2.4, already activated rack-2.2.21 (Gem::LoadError) from /usr/local/lib/ruby/4.0/rubygems/specification.rb:1379:in 'Gem::Specification#activate' from /usr/local/lib/ruby/4.0/rubygems.rb:193:in 'Gem.try_activate' from /home/jeremy/gem-activate-problem.rb:4:in 'Kernel#require' from /home/jeremy/gem-activate-problem.rb:4:in '<main>' /home/jeremy/gem-activate-problem.rb:4:in 'Kernel#require': cannot load such file -- rack/headers (LoadError) from /home/jeremy/gem-activate-problem.rb:4:in '<main>' ``` Same behavior on both OpenBSD and Linux. -- https://bugs.ruby-lang.org/

3 3

[ruby-core:125078] [Ruby Bug#21959] rb_internal_thread_event_hooks_rw_lock is not reinitialized after fork causing deadlocks
by anmarchenko_datadog (Andrey Marchenko) 04 Apr '26

04 Apr '26

Issue #21959 has been reported by anmarchenko_datadog (Andrey Marchenko). ---------------------------------------- Bug #21959: rb_internal_thread_event_hooks_rw_lock is not reinitialized after fork causing deadlocks https://bugs.ruby-lang.org/issues/21959 * Author: anmarchenko_datadog (Andrey Marchenko) * Status: Open * ruby -v: 4.0.1 * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- Ruby's GVL Instrumentation API uses a read-write lock (rb_internal_thread_event_hooks_rw_lock) to protect the list of thread event hooks: - Read lock — acquired on every GVL transition to iterate and call hook callbacks (rb_thread_execute_hooks) - Write lock — acquired when adding/removing hooks (rb_internal_thread_add_event_hook, rb_internal_thread_remove_event_hook) After fork(), Ruby reinitializes several internal locks (e.g. vm->ractor.sched.lock, timer_th.waiting_lock), but not rb_internal_thread_event_hooks_rw_lock. This wasn't added with the GVL Instrumentation API. The full reproducer is available here: https://github.com/anmarchenko/ruby-locks-fork-bug ## Deadlock sequence 1. Parent process has thread event hooks registered (e.g. by a profiler like dd-trace-rb) 2. Multiple threads run concurrently, causing GVL transitions — each transition acquires a read lock on the rwlock 3. fork() happens while a thread holds the read lock 4. In the child, only the forking thread survives — the thread that held the lock is gone, but the lock state is copied as-is 5. Child tries to add or remove a hook → needs write lock → blocks forever on a lock that will never be released 6. Deadlock ## Impact This affects any Ruby C extension using the GVL Instrumentation API in combination with fork-based servers (Resque, Unicorn, Passenger, etc.). The original report comes from dd-trace-rb's profiler deadlocking Resque workers on Alpine Linux (musl libc): https://github.com/DataDog/dd-trace-rb/issues/4967 -- https://bugs.ruby-lang.org/

3 4

[ruby-core:125099] [Ruby Bug#21961] Marshal.load freeze option fail to free linked strings
by byroot (Jean Boussier) 04 Apr '26

04 Apr '26

Issue #21961 has been reported by byroot (Jean Boussier). ---------------------------------------- Bug #21961: Marshal.load freeze option fail to free linked strings https://bugs.ruby-lang.org/issues/21961 * Author: byroot (Jean Boussier) * Status: Open * Backport: 3.2: WONTFIX, 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED ---------------------------------------- ```ruby str = "test" arr = [str, str] strings = Marshal.load(Marshal.dump(arr), freeze: true) p strings.map(&:frozen?) # => [true, false] ``` Expected: `[true, true]` -- https://bugs.ruby-lang.org/

3 2

[ruby-core:125154] [Ruby Bug#21971] Backport commit 5de4cc560864 / PR #15848
by mackuba (Kuba Suder) 04 Apr '26

04 Apr '26

Issue #21971 has been reported by mackuba (Kuba Suder). ---------------------------------------- Bug #21971: Backport commit 5de4cc560864 / PR #15848 https://bugs.ruby-lang.org/issues/21971 * Author: mackuba (Kuba Suder) * Status: Open * ruby -v: ruby 4.0.2 (2026-03-17 revision d3da9fec82) +PRISM [arm64-darwin24] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- Follow-up to ticket: https://bugs.ruby-lang.org/issues/21824 There was a group of old commits merged before 4.0 which were meant to improve regexp performance in some cases. Unfortunately, they also greatly degraded regexp performance in some other cases. This was released in version 4.0.0, where I noticed it when testing the performance of the final version in my app, and reported it as 21824. Chris Hasiński has fixed this on the master branch in commit 5de4cc56086493689701e86aa0ccf6a4a4a87d75, however this wasn't released as a bugfix with Ruby 4.0.1 & 4.0.2. It would be great if this could be backported to the ruby_4_0 branch and included in the 4.0.3 bugfix release. -- https://bugs.ruby-lang.org/

3 3

[ruby-core:125184] [Ruby Feature#21981] Remove CREF rewriting for methods on cloned classes/modules
by jhawthorn (John Hawthorn) 03 Apr '26

03 Apr '26

Issue #21981 has been reported by jhawthorn (John Hawthorn). ---------------------------------------- Feature #21981: Remove CREF rewriting for methods on cloned classes/modules https://bugs.ruby-lang.org/issues/21981 * Author: jhawthorn (John Hawthorn) * Status: Open ---------------------------------------- When a class or module is cloned, Ruby currently rewrites the CREF (constant reference) chain of each copied method so that it points at the new class instead of the original. I don't think this should happen, and methods on a cloned class should retain their original lexical scope. This behaviour was introduced in Ruby 1.9 to fix [Bug #7107], which was reporting that a constant in the original class wasn't available. I think it was done this way because of Ruby's implementation at that time rather than a design choice. This had further changes and fixes in [Bug #10885], [Bug #15877] which were crashes or inconsistencies (stale cache). I'd like us to revisit the design of this behaviour so that it's more intuitive and consistent. ``` ruby class C A = 1 def a; A; end end D = C.clone D.const_set(:A, 2) p C.new.a # => 1 p D.new.a # => 2, but I think it should be 1 ``` In most all other cases in Ruby, methods keep their original lexical scope for constant references: inheritance, mixins, `define_method(..., klass.instance_method(...))`, etc. Cloning a class should behave the same. I think cloning a class is fairly rare, and setting constants on the cloned class more so, but this could be a compatibility issue. This affects `@@class_variables` as well as `CONSTANTS`. FWIW, truffleruby doesn't seem to have this behaviour (which makes sense, part of why I want to remove it is that it's awkward for JIT compiling 😅). https://github.com/ruby/ruby/pull/16651 -- https://bugs.ruby-lang.org/

1 0

[ruby-core:125183] [Ruby Bug#21980] RubyVM::AST offsets are incorrect when BOM
by kddnewton (Kevin Newton) 02 Apr '26

02 Apr '26

Issue #21980 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Bug #21980: RubyVM::AST offsets are incorrect when BOM https://bugs.ruby-lang.org/issues/21980 * Author: kddnewton (Kevin Newton) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- When there is a BOM on a file, the offsets are incorrect for nodes. See: ``` RubyVM::AbstractSyntaxTree.parse("\xEF\xBB\xBF1").source # => "\xEF" ``` -- https://bugs.ruby-lang.org/

1 0

[ruby-core:125167] [Ruby Feature#21976] Add $SECONDS, $RANDOM, and other bashisms
by jhawthorn (John Hawthorn) 02 Apr '26

02 Apr '26

Issue #21976 has been reported by jhawthorn (John Hawthorn). ---------------------------------------- Feature #21976: Add $SECONDS, $RANDOM, and other bashisms https://bugs.ruby-lang.org/issues/21976 * Author: jhawthorn (John Hawthorn) * Status: Open ---------------------------------------- Some time ago there was a lot of discussion around a script named [safe_sleep.sh](https://github.com/actions/runner/blob/af6c8e6eddef233fdef86… in the GitHub Actions runner. Like [many others](https://github.com/actions/runner/issues/2380), I immediately saw the serious problem with this script: it isn't written in Ruby! To better support this use case, and to be able to sleep safely, Ruby should support `$SECONDS` as well as other bashisms like `$RANDOM`, `$1`, etc. This would allow us to rewrite ```bash #!/bin/bash SECONDS=0 while [[ $SECONDS != $1 ]]; do : done ``` In Ruby ```ruby #!/usr/bin/env -S ruby -rbashisms $SECONDS = 0 while $SECONDS != $1.to_i ; end ``` ``` $ ruby -rbashisms -e 'echo $BASH_VERSION' 4.1.2026(4.0.1)-release (ruby) $ ./safe_sleep.rb 5 ``` For ease of evaluating this proposed feature I've have created the [`bashisms` gem](https://github.com/jhawthorn/bashisms) please give it a try! -- https://bugs.ruby-lang.org/

3 2