June 2025 - ruby-core - ml.ruby-lang.org

[ruby-core:119239] [Ruby master Feature#20750] Expose ruby_thread_has_gvl_p in ruby/thread.h
by kbrock (Keenan Brock) 19 Nov '25

19 Nov '25

Issue #20750 has been reported by kbrock (Keenan Brock). ---------------------------------------- Feature #20750: Expose ruby_thread_has_gvl_p in ruby/thread.h https://bugs.ruby-lang.org/issues/20750 * Author: kbrock (Keenan Brock) * Status: Open ---------------------------------------- Hello All, I'm hoping we can make `ruby_thread_has_gvl_p` a public method and no longer experimental. I saw the following code in a gem that was not compiling with ruby 3.3: ``` c // int ruby_thread_has_gvl_p(void); // <== line of concern if (ruby_thread_has_gvl_p()) { method_call(&context); } else { rb_thread_call_with_gvl(method_call, &context); } ``` 400 unique projects on github added the line listed above to fix compilation. [1] Some of the projects detected the method first in `extconf.rb`, but a majority just referenced it. `ffi` used to have the detection code but dropped it since the method was in all supported ruby versions. It feels like this method is now part of the undocumented public interface. My suggestion is to add the method to the real public interface in `ruby/thread.h`. PR with possible solution: https://github.com/ruby/ruby/pull/11619 Also included a patch if that is easier Thank you for your consideration, Keenan Timeline: - Dec 30 2008 - `rb_thread_call_with_gvl` introduced via 9c04a06 [2] - Jan 12 2009 - `ruby_thread_has_gvl_p` introduced via 6f09fc2 [4] - Jul 18 2012 - `rb_thread_call_with_gvl` made public via e9a91d2 [3] Current references to code: `rb_thread_call_with_gvl` [5] `ruby_thread_has_gvl_p` [6]: [1]: https://github.com/search?q=ruby_thread_has_gvl_p+language%3AC++NOT+is%3Afo… [2]: https://github.com/ruby/ruby/commit/9c04a0647fb99f7554cb2e04385ddbb970631e02 [3]: https://github.com/ruby/ruby/commit/e9a91d2c95dfe22ad0487952f7a1053ef9a5fd16 [4]: https://github.com/ruby/ruby/commit/6f09fc2efd1915c4337ce6dded52a8a8771c3222 [5]: https://github.com/ruby/ruby/blob/master/thread.c#L1878 [6]: https://github.com/ruby/ruby/blob/master/thread.c#L1923 ---Files-------------------------------- 11618.patch (3.18 KB) -- https://bugs.ruby-lang.org/

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[ruby-core:121837] [Ruby Feature#21311] Namespace on read (revised)
by tagomoris (Satoshi Tagomori) 19 Nov '25

19 Nov '25

Issue #21311 has been reported by tagomoris (Satoshi Tagomori). ---------------------------------------- Feature #21311: Namespace on read (revised) https://bugs.ruby-lang.org/issues/21311 * Author: tagomoris (Satoshi Tagomori) * Status: Open ---------------------------------------- This replaces #19744 ## Concept This proposes a new feature to define virtual top-level namespaces in Ruby. Those namespaces can require/load libraries (either .rb or native extension) separately from other namespaces. Dependencies of required/loaded libraries are also required/loaded in the namespace. This feature will be disabled by default at first, and will be enabled by an env variable `RUBY_NAMESPACE=1` as an experimental feature. (It could be enabled by default in the future possibly.) ### "on read" approach The "on write" approach here is the design to define namespaces on the loaded side. For example, Java packages are defined in the .java files and it is required to separate namespaces from each other. It can be implemented very easily, but it requires all libraries to be updated with the package declaration. (In my opinion, it's almost impossible in the Ruby ecosystem.) The "on read" approach is to create namespaces and then require/load applications and libraries in them. Programmers can control namespace separation at the "read" time. So, we can introduce the namespace separation incrementally. ## Motivation The "namespace on read" can solve the 2 problems below, and can make a path to solve another problem: * Avoiding name conflicts between libraries * Applications can require two different libraries safely which use the same module name. * Avoiding unexpected globally shared modules/objects * Applications can make an independent/unshared module instance. * Multiple versions of gems can be required * Application developers will have fewer version conflicts between gem dependencies if rubygems/bundler will support the namespace on read. (Support from RubyGems/Bundler and/or other packaging systems will be needed) For the motivation details, see [Feature #19744]. ## How we can use Namespace ```ruby # app1.rb PORT = 2048 class App def self.port = ::PORT def val = PORT.to_s end p App.port # 2048 # app2.rb class Number def double = self * 2 end PORT = 2048.double class App def self.port = ::PORT def val = PORT.double.to_s end p App.port # 4096 # main.rb - executed as `ruby main.rb` ns1 = Namespace.new ns1.require('./app1') # 2048 ns2 = Namespace.new ns2.require('./app2') # 4096 PORT = 8080 class App def self.port = ::PORT def val = PORT.to_s end p App.port # 8080 p App.val # "8080" p ns1::App.port # 2048 p ns1::App.val # "2048" p ns2::App.port # 4096 p ns2::App.val # "8192" 1.double # NoMethodError ``` ## Namespace specification ### Types of namespaces There are two namespace types, "root" and "user" namespace. "Root" namespace exists solely in a Ruby process, and "user" namespaces can be created as many as Ruby programmers want. ### Root namespace Root namespace is a unique namespace to be defined when a Ruby process starts. It only contains built-in classes/modules/constants, which are available without any `require` calls, including RubyGems itself (when `--disable-gems` is not specified). ### User namespace User namespace is a namespace to run users' Ruby scripts. The "main" namespace is the namespace to run the user's `.rb` script specified by the `ruby` command-line argument. Other user namespaces ("optional" namespaces) can be created by `Namespace.new` call. In user namespace (both main and optional namespaces), built-in class/module definitions are copied from the root namespace, and other new classes/modules are defined in the namespace, separately from other (root/user) namespaces. The newly defined classes/modules are top-level classes/modules in the main namespace like `App`, but in optional namespaces, classes/modules are defined under the namespace (subclass of Module), like `ns::App`. In that namespace `ns`, `ns::App` is accessible as `App` (or `::App`). There is no way to access `App` in the main namespace from the code in the different namespace `ns`. ### Constants, class variables and global variables Constants, Class variables of built-in classes and global variables are also separated by namespace. Values set to class/global variables in a namespace are invisible in other namespaces. ### Methods and procs Methods defined in a namespace run with the defined namespace, even when called from other namespaces. Procs created in a namespace run with the defined namespace too. ### Dynamic link libraries Dynamic link libraries (typically .so files) are also loaded in namespaces as well as .rb files. ### Open class (Changes on built-in classes) In user namespaces, built-in class definitions can be modified. But those operations are processed as copy-on-write of class definition from the root namespace, and the changed definitions are visible only in the (user) namespace. Definitions in the root namespace are not modifiable from other namespaces. Methods defined in the root namespace run only with root-namespace definitions. ## Enabling Namespace Specify `RUBY_NAMESPACE=1` environment variable when starting Ruby processes. `1` is the only valid value here. Namespace feature can be enabled only when Ruby processes start. Setting `RUBY_NAMESPACE=1` after starting Ruby scripts performs nothing. ## Pull-request https://github.com/ruby/ruby/pull/13226 -- https://bugs.ruby-lang.org/

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[ruby-core:122303] [Ruby Bug#21375] Set[] does not call #initialize
by Ethan (Ethan -) 18 Nov '25

18 Nov '25

Issue #21375 has been reported by Ethan (Ethan -). ---------------------------------------- Bug #21375: Set[] does not call #initialize https://bugs.ruby-lang.org/issues/21375 * Author: Ethan (Ethan -) * Status: Open * ruby -v: ruby 3.5.0dev (2025-05-26T17:42:35Z master 909a0daab6) +PRISM [x86_64-darwin22] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- I have a subclass of Set that overrides #initialize. Following #21216, .new does call #initialize but .[] does not. ```ruby class MySet < Set def initialize(enum = nil) compare_by_identity super end end MySet.new.compare_by_identity? # => true MySet[].compare_by_identity? # => false ``` -- https://bugs.ruby-lang.org/

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[ruby-core:122411] [Ruby Bug#21396] Set#initialize should call Set#add on items passed in
by tenderlovemaking (Aaron Patterson) 18 Nov '25

18 Nov '25

Issue #21396 has been reported by tenderlovemaking (Aaron Patterson). ---------------------------------------- Bug #21396: Set#initialize should call Set#add on items passed in https://bugs.ruby-lang.org/issues/21396 * Author: tenderlovemaking (Aaron Patterson) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```ruby class Foo < Set def add(item) = super(item.bytesize) end x = Foo.new(["foo"]) p x p x.include?(3) ``` On Ruby 3.4 the output is this: ``` > ruby -v test.rb ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [arm64-darwin24] #<Foo: {3}> true ``` On Ruby master the output is this: ``` > make run ./miniruby -I./lib -I. -I.ext/common -r./arm64-darwin24-fake ./test.rb #<Set: {"foo"}> false ``` The bug is that `initialize` is not calling `add` for the elements passed in, so the subclass doesn't get a chance to change them. I've sent a PR here: https://github.com/ruby/ruby/pull/13518 -- https://bugs.ruby-lang.org/

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[ruby-core:119998] [Ruby master Bug#20907] Fiber scheduler does not correctly re-lock mutex if `Mutex#sleep` is interrupted.
by ioquatix (Samuel Williams) 17 Nov '25

17 Nov '25

Issue #20907 has been reported by ioquatix (Samuel Williams). ---------------------------------------- Bug #20907: Fiber scheduler does not correctly re-lock mutex if `Mutex#sleep` is interrupted. https://bugs.ruby-lang.org/issues/20907 * Author: ioquatix (Samuel Williams) * Status: Open * Assignee: ioquatix (Samuel Williams) * Backport: 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED ---------------------------------------- The following test fails with a `ThreadError` instead of a `RuntimeError`: ```ruby def test_condition_variable condition_variable = ::Thread::ConditionVariable.new mutex = ::Thread::Mutex.new error = nil thread = Thread.new do Thread.current.report_on_exception = false scheduler = Scheduler.new Fiber.set_scheduler scheduler fiber = Fiber.schedule do begin mutex.synchronize do condition_variable.wait(mutex) end rescue => error end end fiber.raise(RuntimeError) end thread.join assert_kind_of RuntimeError, error end ``` Fix: https://github.com/ruby/ruby/pull/12158 -- https://bugs.ruby-lang.org/

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[ruby-core:121688] [Ruby Feature#21275] Update to Unicode 17.0
by duerst 14 Nov '25

14 Nov '25

Issue #21275 has been reported by duerst (Martin Dürst). ---------------------------------------- Feature #21275: Update to Unicode 17.0 https://bugs.ruby-lang.org/issues/21275 * Author: duerst (Martin Dürst) * Status: Open * Assignee: duerst (Martin Dürst) * Target version: 3.5 ---------------------------------------- Unicode 17.0 is currently in alpha. Beta is planned for late May, release for September 2025. We just updated to Unicode 16.0, so we can start testing with alpha/beta. -- https://bugs.ruby-lang.org/

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[ruby-core:119895] [Ruby master Bug#20889] IO#ungetc and IO#ungetbyte should not cause IO#pos to report an inaccurate position
by javanthropus (Jeremy Bopp) 13 Nov '25

13 Nov '25

Issue #20889 has been reported by javanthropus (Jeremy Bopp). ---------------------------------------- Bug #20889: IO#ungetc and IO#ungetbyte should not cause IO#pos to report an inaccurate position https://bugs.ruby-lang.org/issues/20889 * Author: javanthropus (Jeremy Bopp) * Status: Open * ruby -v: ruby 3.3.6 (2024-11-05 revision 75015d4c1f) [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- ```ruby require 'tempfile' Tempfile.open(encoding: 'utf-8') do |f| f.write('0123456789') f.rewind f.ungetbyte(93) f.pos # => -1; negative value is surprising! end Tempfile.open(encoding: 'utf-8') do |f| f.write('0123456789') f.rewind f.ungetc('a'.encode('utf-8')) f.pos # => -1; similar to the ungetbyte case end Tempfile.open(encoding: 'utf-8:utf-16le') do |f| f.write('0123456789') f.rewind f.ungetc('a'.encode('utf-16le')) f.pos # => 0; maybe should be -2 to match the previous ungetc case? end ``` It doesn't seem logical that `IO#pos` should ever be affected by `IO#ungetc` or `IO#ungetbyte`. The pushed characters or bytes aren't really in the stream source. The value of `IO#pos` implies that jumping directly to that position via `IO#seek` and reading from there would return the same character or byte that was pushed, but the pushed characters or bytes are lost when the operation to seek in the stream is performed. In the case where `IO#pos` is a negative value, attempting to seek to that position actually raises an exception. In the `IO#ungetc` with character conversion case above, it seems unreasonable to make `IO#pos` report an even less correct position. In that case, the position would need to be adjusted by 2 bytes in reverse due to the internal encoding of the stream, but that is completely inconsistent with the behavior of `IO#pos` when reading from the stream normally where it reports the underlying stream's byte position and not the number of transcoded bytes that have been read: ```ruby require 'tempfile' Tempfile.open(encoding: 'utf-8:utf-16le') do |f| f.write('0123456789') f.rewind f.getc.bytesize # => 2; due to the internal encoding of the stream f.pos # => 1; reports actual bytes read from the stream, not transcoded bytes end ``` Attempting to use `IO#pos` when there are characters or bytes pushed into the read buffer by way of `IO#ungetc` or `IO#ungetbyte` should result in one of the following behaviors: 1. Raise and exception 2. Return the stream's position, clearing the read buffer entirely 3. Return the stream's position, ignoring the pushed characters or bytes, and produce a warning -- https://bugs.ruby-lang.org/

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[ruby-core:122343] [Ruby Misc#21385] Namespace: Suggesting a rename
by fxn (Xavier Noria) 11 Nov '25

11 Nov '25

Issue #21385 has been reported by fxn (Xavier Noria). ---------------------------------------- Misc #21385: Namespace: Suggesting a rename https://bugs.ruby-lang.org/issues/21385 * Author: fxn (Xavier Noria) * Status: Open ---------------------------------------- I'd like to suggest a rename of namespaces. The word "namespace" is already taken in Ruby. We say that classes and modules act as or represent. Constant paths nest them in practice. We say that it is a best practice that gems create their own namespace, etc. If the feature goes ahead with this name, the above sentences, well-established in the Ruby community, will start to sound confusing, because that meaning of "namespace" stays. If you look at the index in Matz's book, "namespaces" is indexed in pages 248–250. Title of section 7.5.1 is "Modules as Namespaces". Besides, I have had a few experiences explaining the proposal to people, and quickly realizing they assume this is something like C++ namespaces or Java packages. Then, I have to undo that mental model and start all over saying "forget that mental model". Those are like our constant paths, only more simple and strict. I think it may also be confusing in this sense (though this could be OK if it wasn't for the previous point.) To be constructive: Some alternative names that I have thought about are "isolates", "shields", or "cells". ("sandboxes" is close, but may have security connotations you do not want to suggest.) -- https://bugs.ruby-lang.org/

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[ruby-core:117434] [Ruby master Bug#20409] Missing reporting some invalid breaks
by kddnewton (Kevin Newton) 06 Nov '25

06 Nov '25

Issue #20409 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Bug #20409: Missing reporting some invalid breaks https://bugs.ruby-lang.org/issues/20409 * Author: kddnewton (Kevin Newton) * Status: Open * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- -- https://bugs.ruby-lang.org/

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[ruby-core:116382] [Ruby master Feature#20205] Enable `frozen_string_literal` by default
by byroot (Jean Boussier) 28 Oct '25

28 Oct '25

Issue #20205 has been reported by byroot (Jean Boussier). ---------------------------------------- Feature #20205: Enable `frozen_string_literal` by default https://bugs.ruby-lang.org/issues/20205 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context The `frozen_string_literal: true` pragma was introduced in Ruby 2.3, and as far as I'm aware the plan was initially to make it the default for Ruby 3.0, but this plan was abandoned because it would be too much of a breaking change without any real further notice. According to Matz, he still wishes to enable `frozen_string_literal` by default in the future, but a reasonable migration plan is required. The main issue is backward compatibility, flipping the switch immediately would break a lot of code, so there must be some deprecation period. The usual the path forward for this kind of change is to emit deprecation warnings one of multiple versions in advance. One example of that was the Ruby 2.7 keyword argument deprecation. It was quite verbose, and some users were initially annoyed, but I think the community pulled through it and I don't seem to hear much about it anymore. So for frozen string literals, the first step would be to start warning when a string that would be frozen in the future is mutated. ### Deprecation Warning Implementation I implemented a quick proof of concept with @etienne in https://github.com/Shopify/ruby/pull/549 In short: - Files with `# frozen_string_literal: true` or `# frozen_string_literal: false` don't change in behavior at all. - Files with no `# frozen_string_literal` comment are compiled to use `putchilledstring` opcode instead of regular `putstring`. - This opcode mark the string with a user flag, when these strings are mutated, a warning is issued. Currently the proof of concept issue the warning at the mutation location, which in some case can make locating where the string was allocated a bit hard. But it is possible to improve it so the message also include the location at which the literal string was allocated, and learning from the keyword argument warning experience, we can record which warnings were already issued to avoid spamming users with duplicated warnings. As currently implemented, there is almost no overhead. If we modify the implementation to record the literal location, we'd incur a small memory overhead for each literal string in a file without an explicit `frozen_string_literal` pragma. But I believe we could do it in a way that has no overhead if `Warning[:deprecated] = false`. ### Timeline The migration would happen in 3 steps, each step can potentially last multiple releases. e.g. `R0` could be `3.4`, `R1` be `3.7` and `R2` be `4.0`. I don't have a strong opinion on the pace. - Release `R0`: introduce the deprecation warning (only if deprecation warnings enabled). - Release `R1`: make the deprecation warning show up regardless of verbosity level. - Release `R2`: make string literals frozen by default. ### Impact Given that `rubocop` is quite popular in the community and it has enforced the usage of `# frozen_string_literal: true` for years now, I suspect a large part of the actively maintained codebases in the wild wouldn't see any warnings. And with recent versions of `minitest` enabling deprecation warnings by default (and [potentially RSpec too](https://github.com/rspec/rspec-core/issues/2867)) the few that didn't migrate will likely be made compatible quickly. The real problem of course are the less actively developed libraries and applications. For such cases, any codebase can remain compatible by setting `RUBYOPT="--disable=frozen_string_literal"`, and so even after `R2` release. The flag would never be removed any legacy codebase can continue upgrading Ruby without changing a single line of cod by just flipping this flag. ### Workflow for library maintainers As a library maintainer, fixing the deprecation warnings can be as simple as prepending `# frozen_string_literal: false` at the top of all their source files, and this will keep working forever. Alternatively they can of course make their code compatible with frozen string literals. Code that is frozen string literal compatible doesn't need to explicitly declare it. Only code that need it turned of need to do so. ### Workflow for application owners For application owners, the workflow is the same than for libraries. However if they depend on a gem that hasn't updated, or that they can't upgrade it, they can run their application with `RUBYOPT="--disable=frozen_string_literal"` and it will keep working forever. Any user running into an incompatibility issue can set `RUBYOPT="--disable=frozen_string_literal"` forever, even in `4.x`, the only thing changing is the default value. And any application for which all dependencies have been made fully frozen string literal compatible can set `RUBYOPT="--enable=frozen_string_literal"` and start immediately removing magic comment from their codebase. -- https://bugs.ruby-lang.org/

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