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

[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/

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[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/

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[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/

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[ruby-core:125161] [Ruby Bug#21974] Cannot inspect RubyVM::AST for CDECL
by kddnewton (Kevin Newton) 02 Apr '26

02 Apr '26

Issue #21974 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Bug #21974: Cannot inspect RubyVM::AST for CDECL https://bugs.ruby-lang.org/issues/21974 * Author: kddnewton (Kevin Newton) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ``` ./ruby -e 'pp RubyVM::AbstractSyntaxTree.parse("::Foo = 1")' ``` and ``` ./ruby -e 'p RubyVM::AbstractSyntaxTree.parse("::Foo = 1").children[2].children' ``` both crash -- https://bugs.ruby-lang.org/

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[ruby-core:125180] [Ruby Feature#21979] `String#unpack`/`String#unpack1` should allow negative offset
by nobu (Nobuyoshi Nakada) 02 Apr '26

02 Apr '26

Issue #21979 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Feature #21979: `String#unpack`/`String#unpack1` should allow negative offset https://bugs.ruby-lang.org/issues/21979 * Author: nobu (Nobuyoshi Nakada) * Status: Open ---------------------------------------- https://bugs.ruby-lang.org/issues/18254#note-14 I think `String#unpack`/`String#unpack1` should allow negative offset as well as the other methods, for example `String#slice` that is referred to in the description. -- https://bugs.ruby-lang.org/

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[ruby-core:125179] [Ruby Feature#18254] Add an `offset` parameter to String#unpack and String#unpack1
by nobu (Nobuyoshi Nakada) 02 Apr '26

02 Apr '26

Issue #18254 has been updated by nobu (Nobuyoshi Nakada). I wasn't aware that negative offset is not allowed. Shouldn't `unpack`/`unpack1` also it as well as the other methods, `String#slice`, `String#[]` and so on? ---------------------------------------- Feature #18254: Add an `offset` parameter to String#unpack and String#unpack1 https://bugs.ruby-lang.org/issues/18254#change-116911 * Author: byroot (Jean Boussier) * Status: Closed ---------------------------------------- When working with binary protocols it's common to have to first unpack some kind of header or type prefix, and then based on that unpack another part of the string. For instance here's [a code snippet from Dalli, the most common Memcached client](https://github.com/petergoldstein/dalli/blob/76b79d78cda13562da17bc…: ```ruby while buf.bytesize - pos >= 24 header = buf.slice(pos, 24) (key_length, _, body_length, cas) = header.unpack(KV_HEADER) if key_length == 0 # all done! @multi_buffer = nil @position = nil @inprogress = false break elsif buf.bytesize - pos >= 24 + body_length flags = buf.slice(pos + 24, 4).unpack1("N") key = buf.slice(pos + 24 + 4, key_length) value = buf.slice(pos + 24 + 4 + key_length, body_length - key_length - 4) if body_length - key_length - 4 > 0 pos = pos + 24 + body_length begin values[key] = [deserialize(value, flags), cas] rescue DalliError end else # not enough data yet, wait for more break end end @position = pos ``` ### Proposal If `unpack` and `unpack1` had an `offset:` parameter, it would allow this kind of code to extract the fields it needs without allocating and copying as much strings, e.g.: ```ruby flags = buf.slice(pos + 24, 4).unpack1("N") ``` could be: ```ruby buf.unpack1("N", offset: pos + 24) ``` -- https://bugs.ruby-lang.org/

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[ruby-core:125164] [Ruby Feature#21975] Add "UTF-八" as an alias for UTF-8 encoding
by ko1 (Koichi Sasada) 02 Apr '26

02 Apr '26

Issue #21975 has been reported by ko1 (Koichi Sasada). ---------------------------------------- Feature #21975: Add "UTF-八" as an alias for UTF-8 encoding https://bugs.ruby-lang.org/issues/21975 * Author: ko1 (Koichi Sasada) * Status: Open ---------------------------------------- In Japan, legal texts must write all characters - including digits - using full-width or kanji forms. As a result, the encoding name "UTF-8" appears as "UTF-八" (八 = eight in kanji) in official government notices. Specifically, it appears in a notice issued by the Digital Agency and the Ministry of Internal Affairs and Communications (令和8年デジタル庁・総務省告示第12号), which defines character sets and encoding for local government information systems: > 地方公共団体情報システムの標準化に関する法律第七条第一項に規定する各地方公共団体情報システムに共通する基準のうち電磁的記録において用いられる用語及び符号の相互運用性の確保その他の地方公共団体情報システムに係る互換性の確保に関する標準を定める命令第三条第二号の規定に基づき行政事務標準文字の文字セット及び地方公共団体情報システム間の連携のための文字符号化方式を定める告示 Reference: https://www.digital.go.jp/assets/contents/node/basic_page/field_ref_resourc… This patch <https://github.com/ruby/ruby/pull/16623> adds "UTF-八" as an encoding alias for UTF-8, so that Ruby is compliant with Japanese law. ```ruby # encoding: UTF-八 p __ENCODING__ #=> #<Encoding:UTF-8> p Encoding.find("UTF-八") #=> #<Encoding:UTF-8> p "hello".encode("UTF-八") #=> "hello" p "こんにちは".force_encoding("UTF-八") #=> "こんにちは" p "こんにちは".encode("ＵＴＦ｜八") #=> "こんにちは" ``` -- https://bugs.ruby-lang.org/

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[ruby-core:125176] [Ruby Bug#21978] Fix class variable cache isn't invalidated via modules
by jhawthorn (John Hawthorn) 01 Apr '26

01 Apr '26

Issue #21978 has been reported by jhawthorn (John Hawthorn). ---------------------------------------- Bug #21978: Fix class variable cache isn't invalidated via modules https://bugs.ruby-lang.org/issues/21978 * Author: jhawthorn (John Hawthorn) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ```ruby module M; @@x = 1; end class A; end class B < A include M def self.x; @@x; end end B.x # warm cache A.class_variable_set(:@@x, 2) B.x ``` The last call to `B.x` should fail with `Should raise: class variable @@x of M is overtaken by A (RuntimeError)`, but has been returning 1 since since ruby-3.2.0-preview3. It should be solvable by by bumping the global state counter more aggressively: https://github.com/ruby/ruby/pull/16551 -- https://bugs.ruby-lang.org/

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[ruby-core:125174] [Ruby Bug#21977] Ruby::Box crash with `RUBY_BOX=1` via `Binding` refinement, `UnboundMethod#bind_call`, and `Symbol#to_proc`
by singetu0096 (Rintaro Kawasugi) 01 Apr '26

01 Apr '26

Issue #21977 has been reported by singetu0096 (Rintaro Kawasugi). ---------------------------------------- Bug #21977: Ruby::Box crash with `RUBY_BOX=1` via `Binding` refinement, `UnboundMethod#bind_call`, and `Symbol#to_proc` https://bugs.ruby-lang.org/issues/21977 * Author: singetu0096 (Rintaro Kawasugi) * Status: Open * ruby -v: ruby 4.1.0dev (2026-03-24T21:47:14Z master 30dcc2a082) +PRISM [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ## Summary I found a reproducible interpreter crash when Ruby is run with `RUBY_BOX=1`. A refinement on `Binding`, combined with `UnboundMethod#bind_call` and `Symbol#to_proc`, causes Ruby to abort with: ```text [BUG] BUG: Local ep without cme/box, flags: 66660087 ``` I reproduced this on: ```text ruby 4.1.0dev (2026-03-24T21:47:14Z master 30dcc2a082) +PRISM [x86_64-linux] ``` Follow-up validation confirmed an important discriminator: replacing `map(&:to_s)` with an explicit block such as `map { _1.to_s }` avoids the crash. The currently available evidence therefore points to a box/frame bookkeeping bug in the `Symbol#to_proc` path that reaches an explicit internal `rb_bug(...)` assertion, not to confirmed memory corruption. ## PoC ```ruby using Module.new { refine ::Binding do def eval_methods ::Kernel.instance_method(:methods).bind_call(receiver) end end } p binding.eval_methods.map(&:to_s) ``` Run: ```bash RUBY_BOX=1 ./miniruby -e ' using Module.new { refine ::Binding do def eval_methods ::Kernel.instance_method(:methods).bind_call(receiver) end end } p binding.eval_methods.map(&:to_s) ' ``` Observed result: ```text [BUG] BUG: Local ep without cme/box, flags: 66660087 ruby 4.1.0dev (2026-03-24T21:47:14Z master 30dcc2a082) +PRISM [x86_64-linux] Crashed while printing bug report ``` Important discriminator: ```ruby p binding.eval_methods.map { _1.to_s } ``` Replacing `map(&:to_s)` with an explicit block avoids the crash, which strongly suggests that the failure depends specifically on the `Symbol#to_proc` path rather than `map` in general. ## Impact The currently confirmed impact is denial of service in processes using Ruby::Box with `RUBY_BOX=1`. Confirmed claim: - reliable interpreter abort - trigger requires `RUBY_BOX=1` - trigger depends specifically on the `Symbol#to_proc` path in this setup Current non-claims: - no confirmed memory corruption - no confirmed sandbox escape - no confirmed privilege escalation - no confirmed arbitrary code execution This report should remain separate from the Ruby::Box double-free issue, because the trigger path, failure mode, and currently demonstrated impact are different. -- https://bugs.ruby-lang.org/

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[ruby-core:125156] [Ruby Feature#21972] Add Date.birthday and Date.age to track Ruby's milestones
by jinroq (Jinroq SAITOH) 01 Apr '26

01 Apr '26

Issue #21972 has been reported by jinroq (Jinroq SAITOH). ---------------------------------------- Feature #21972: Add Date.birthday and Date.age to track Ruby's milestones https://bugs.ruby-lang.org/issues/21972 * Author: jinroq (Jinroq SAITOH) * Status: Open ---------------------------------------- Since its inception in 1993, Ruby has grown beyond a mere programming language to become a rich culture beloved by developers worldwide. However, the standard `date` library surprisingly lacks a formal interface to commemorate Ruby's own historical milestones. The fact that developers cannot programmatically reference Ruby’s heritage is a missed opportunity to foster affection and respect for the language's identity. To rectify this historical oversight, I propose adding the following methods to reference Ruby's key anniversaries and calculate the elapsed years. #### New Features * **`Date.birthday(version = nil)`** Returns the "birthday" of significant moments in Ruby's history. * `nil` (default): **1993-02-24** (The day the name "Ruby" was decided). * `0.95`: **1995-12-21** (The first public release date). * `1.0`: **1996-12-25** (The first stable release date). * **`Date.age(version = nil)`** Calculates the current age (in full years) based on today's date and the specified milestone. * `Date.age`: Years since the name "Ruby" was born. * `Date.age(0.95)`: Years since Ruby was first introduced to the public as OSS. * `Date.age(1.0)`: Years since Ruby began its journey as a stable language. #### Usage Example ```ruby # Check the "age" of each edition puts "Name age: #{Date.age}" # => 33 (as of 2026) puts "OSS age: #{Date.age(0.95)}" # => 30 puts "Stable: #{Date.age(1.0)}" # => 29 # Perform a special action on a specific anniversary if Date.today == Date.birthday(1.0) celebrate_stable_anniversary! end ``` #### Implementation and Testing The attached patch (`birthday_and_age.patch`) includes the implementation of these methods along with a rigorous test suite (`test/date/test_date_birthday.rb`). The tests cover argument dispatching, `ArgumentError` for invalid inputs, and edge cases for age calculation (e.g., boundaries before and after the actual birthday), ensuring production-level quality. Equipping Ruby with the intelligence to reflect upon its own origins is a vital step toward the next 30 or 40 years of its evolution. (Note: This proposal was submitted on a special day that encourages looking at our history with both deep respect and a touch of creative imagination, as is traditional for such a significant date in the calendar.) ---Files-------------------------------- birthday_and_age.patch (8.08 KB) -- https://bugs.ruby-lang.org/

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