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

[ruby-core:122355] [Ruby Feature#21389] Simplify Set#inspect output
by jeremyevans0 (Jeremy Evans) 14 Dec '25

14 Dec '25

Issue #21389 has been reported by jeremyevans0 (Jeremy Evans). ---------------------------------------- Feature #21389: Simplify Set#inspect output https://bugs.ruby-lang.org/issues/21389 * Author: jeremyevans0 (Jeremy Evans) * Status: Open ---------------------------------------- As Set is now a core collection class, it should have special inspect output. Ideally, inspect output should be suitable to eval, similar to array and hash (assuming the elements are also suitable to eval): ```ruby set = Set[1, 2, 3] eval(set.inspect) == set # should be true ``` The simplest way to do this is to use the Set[] syntax: ```ruby Set[1, 2, 3].inspect # => "Set[1, 2, 3]" ``` I've submitted a pull request that implements this: https://github.com/ruby/ruby/pull/13488 The pull request deliberately does not use any subclass name in the output, similar to array and hash. I think it is more important that users know they are dealing with a set than which subclass: ```ruby Class.new(Set)[] # PR does: Set[] # not: #<Class:0x00000c21c78699e0>[] ``` However, it's easy to change the PR to use a subclass name if that is desired. -- https://bugs.ruby-lang.org/

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[ruby-core:119380] [Ruby master Misc#20774] Remove remaining locale dependent code from Windows port
by larskanis (Lars Kanis) 12 Dec '25

12 Dec '25

Issue #20774 has been reported by larskanis (Lars Kanis). ---------------------------------------- Misc #20774: Remove remaining locale dependent code from Windows port https://bugs.ruby-lang.org/issues/20774 * Author: larskanis (Lars Kanis) * Status: Open ---------------------------------------- The external_encoding of files, file names and ENV on Windows were changed from locale codepage to UTF-8 in ruby-3.0. But there are still several remaining points where locale encoding is used although there is no need to do so. The Windows port is already fully UTF-16/UTF-8 based and locale encoding is only used for historical and not for technical reasons. My proposal is to remove (most of) the locale dependent conversions from the ruby code for Windows. Before I open pull requests in this regard, I would like to confirm this direction with the ruby core team. Let me show what I mean: ``` # täst-locale-enc.rb def pr(*strs) strs.each do |str| p [str, IO===str ? str.external_encoding&.name : str.encoding.name] end end if $0==__FILE__ pr STDIN # => [#<IO:<STDIN>>, "CP850"] pr $0 # => ["ruby/t\x84st-locale-enc.rb", "CP850"] pr __FILE__ # => ["ruby/t\x84st-locale-enc.rb", "CP850"] pr __dir__ # => ["C:/Users/kanis/ruby", "CP850"] pr 'ä' # => ["ä", "UTF-8"] pr '€' # => ["€", "UTF-8"] pr $:.first # => ["C:/Users/kanis/t\xE2\x82\xACst", "ASCII-8BIT"] pr $:.last # => ["C:/Ruby33-x64/lib/ruby/3.3.0/x64-mingw-ucrt", "CP850"] require "win32/registry" pr Win32::Registry::HKEY_CURRENT_USER.open("Environment")['TMP'] # => ["C:\\Users\\kanis\\AppData\\Local\\Temp", "UTF-8"] pr Win32::Registry::HKEY_CURRENT_USER.open("\\").each_key{ break _1 } # => ["AppEvents", "CP850"] end # execute with: ruby -It€st ruby\täst-locale-enc.rb ``` I wrote the results on `ruby-3.3 x64-mingw-ucrt` right into the code. The situation is even worse when called with `-e` script: ``` $ ruby -It€st -r .\ruby\täst-locale-enc.rb -e "pr STDIN, $0, __FILE__, __dir__, 'ä', '€', $:.first, $:.last" [#<IO:<STDIN>>, "CP850"] ["-e", "CP850"] ["-e", "UTF-8"] [".", "US-ASCII"] ["\x84", "CP850"] ["?", "CP850"] ["C:/Users/kanis/t\xE2\x82\xACst", "ASCII-8BIT"] ["C:/Ruby33-x64/lib/ruby/3.3.0/x64-mingw-ucrt", "CP850"] ``` There are also some inconsistencies like that it's possible to `require` script names with characters outside of the codepage, but it fails to execute a script directly or by using `require_relative` : ``` $ ruby -r .\t€st-locale-enc.rb -e "pr STDIN" [#<IO:<STDIN>>, "CP850"] $ ruby .\t€st-locale-enc.rb ruby: Invalid argument -- ./t?st-locale-enc.rb (LoadError) ``` Maybe there are more places which are working with locale codepage - these are only the few that I remember from memory. I would like to change all the above results to be UTF-8 encoded, like it is the case on Ubuntu. Compatibility ------------- Changing the encoding of returned strings is of course an API change. IMHO it is still something we should change in a minor release of ruby. The reason is that I don't remember about only a single issue cased by the change to UTF-8 in ruby-3.0 in the company I work for. To the contrary many issues are caused by using locale codepage where some non-ASCII characters work and other characters don't. Most issue with ruby-3.0 were cased by the keyword argument changes. -- https://bugs.ruby-lang.org/

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[ruby-core:120279] [Ruby master Feature#20959] Add a way to get codepage of console.
by YO4 (Yoshinao Muramatsu) 11 Dec '25

11 Dec '25

Issue #20959 has been reported by YO4 (Yoshinao Muramatsu). ---------------------------------------- Feature #20959: Add a way to get codepage of console. https://bugs.ruby-lang.org/issues/20959 * Author: YO4 (Yoshinao Muramatsu) * Status: Open ---------------------------------------- # Abstract Add a way to retrieve code pages of console. On Windows, Encoding.find("locale") returns the console codepage. To prepare for future changes, specify ```console``` instead of ```locale``` to get the encoding when a console code page is needed. # Background On Windows, Encoding.find("locale") returns the console codepage. This is different from locale in other environments. Also the name and content do not seem to match. In the future, if we change the locale_encoding of the Windows port to the locale codepage of the C runtime library, we need to get the encoding for the console. Strings received via pipe from cmd.exe or powershell are encoded in the console codepage. This would be necessary when communicating with other programs via pipes. # Proposal Make Encoding.find("console") return the encoding that represents the console codepage. # Background(continued) Since Windows 10, UTF-8 support seems to be enhanced in the commandline environment. * build 17134 ucrt supports UTF-8 locale codepage ```setlocale(LC_CTYPE, ".utf8")``` Windows support UTF-8 ANSI Codepage(experimental) ```Beta: Use Unicode UTF-8 for worldwide language support``` * build 18362 support ```Set a process code page to UTF-8``` via manifest. * build 19041 Time zone name holds in wchar_t internaly, so proper tzname can be obtained regardless of the Windows language setting. This should not be all. Through these, I feel that the Microsoft team recommends the use of utf-8. It also seems that Microsoft, which has previously depricated the ANSI version of the API, is treating it as a valid alternative to use in UTF-8. If it becomes widespread on Windows for libraries to respect the C runtime library locale, ruby would do better to follow it. Of course, it is good to be able to get the encoding of the console by specifying a console. # Future plan By reducing differences from other platforms, bugs and extra code are hoped to be reduced. * Do ```setlocale(LC_CTYPE, ".utf8");``` in main.c (or refer LC_* environment variables). * ```Encoding.find("locale")``` returns C runtime library locale. Since strings obtained from the Windows system have a Unicode code range, the API to obtain fixed UTF-8 encoding remains unchanged. # Discussion The code page we can get from Windows also has ACP and OEMCP, but are these necessary? Is it reasonable to get locale_encoding if Encoding.find("console") is called on other platforms? -- https://bugs.ruby-lang.org/

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[ruby-core:117003] [Ruby master Bug#20314] Simultaneous Timeout expires may raise an exception after the block
by mame (Yusuke Endoh) 11 Dec '25

11 Dec '25

Issue #20314 has been reported by mame (Yusuke Endoh). ---------------------------------------- Bug #20314: Simultaneous Timeout expires may raise an exception after the block https://bugs.ruby-lang.org/issues/20314 * Author: mame (Yusuke Endoh) * Status: Open * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Launchable reports `TestTimeout#test_nested_timeout` as a flaky test, and I reproduced it as follows. ```ruby require "timeout" class A < Exception end class B < Exception end begin Timeout.timeout(0.1, A) do Timeout.timeout(0.1, B) do nil while true end end rescue A, B p $! #=> #<A: execution expired> # Exception B is raised after the above call returns #=> test.rb:16:in `p': execution expired (B) p :end # not reach end ``` This is because the timer thread performs two consecutive `Thread#raise` to the target thread. I have discussed this with @ko1 and have come up with three solutions. ### Solution 1 When multiple nested Timeouts expire simultaneously, raise an exception for the outer-most Timeout and let the inner Timeouts expire without throwing an exception. In the above example, it would only raise A. The problem with this approach is that if you are rescuing A in the inner block, it may never ends: ```ruby Timeout.timeout(0.1, A) do Timeout.timeout(0.1, B) do begin sleep rescue A sleep # The exception A is caught. The inner Timeout is already expired, so the code (may) never end. end end end ``` Note that, if A and B did not occur at the same time, it would raise B. This is a race condition. ### Solution 2 When multiple nested Timeouts expire simultaneously, raise an exception for the inner-most Timeout and let the outer Timeouts wait until the inner-most Timeout returns. In the above example, it would raise either A or B, not both. The problem with this approach is that if you are rescuing B in the inner block, it never ends: ```ruby Timeout.timeout(0.1, A) do Timeout.timeout(0.1, B) do begin sleep rescue B sleep # The outer Timeout waits for the inner timeout, and the inner Timeout never return. So this code never ends. end end end ``` ### Solution 3 Make thread interrupt queue one length. If the target thread has already been `Thread#raise(A)`, the new `Thread#raise(B)` blocks until the target thread processes A. Since there will be no more simultaneous Thread#raise, there will be no more exceptions after the end of the block. The timeout timer thread should be changed in consideration that `Thread#raise` may block. -- https://bugs.ruby-lang.org/

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[ruby-core:123261] [Ruby Bug#21607] require 'concurrent-ruby' causes segfault with Ruby 3.4.6 on linux/i686
by satadru (Satadru Pramanik) 11 Dec '25

11 Dec '25

Issue #21607 has been reported by satadru (Satadru Pramanik). ---------------------------------------- Bug #21607: require 'concurrent-ruby' causes segfault with Ruby 3.4.6 on linux/i686 https://bugs.ruby-lang.org/issues/21607 * Author: satadru (Satadru Pramanik) * Status: Open * ruby -v: ruby 3.4.6 (2025-09-16 revision dbd83256b1) +PRISM [i686-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- As mentioned at https://github.com/ruby/ruby/pull/14532#issuecomment-3288983469 chronos@buppie-i686:2.23 M58 /usr/local/lib/crew/packages (master >|SPARSE)$ ruby -e "require 'concurrent-ruby' ; puts 'success'" Segmentation fault This causes a segfault on i686 only on our Chromebrew/i686 systems. armv7l and x86_64 do not have this issue. This may be linked to the update to prism 1.5.x? Docker reproducer on our i686 ChromeOS Milestone 58 based container image: docker run --init --platform linux/386 --rm --net=host -v $(pwd):/output -h $(hostname)-i686 --tmpfs /tmp --ulimit "nofile=$(ulimit -Sn):$(ulimit -Hn)" -it satmandu/crewbuild:alex-i686.m58 # Note the lack of an issue with 3.4.5 with this command: ruby -e "require 'concurrent-ruby' ; puts 'success'" # In that container, upgrade ruby to 3.4.6: CREW_REPO=https://github.com/chromebrew/chromebrew.git CREW_BRANCH=updater-ruby_3.4.6 crew update \ && yes | crew upgrade # Then run the breaking command: ruby -e "require 'concurrent-ruby' ; puts 'success'" # Note the segfault. -- https://bugs.ruby-lang.org/

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[ruby-core:115196] [Ruby master Feature#19979] Allow methods to declare that they don't accept a block via `&nil`
by ufuk (Ufuk Kayserilioglu) 11 Dec '25

11 Dec '25

Issue #19979 has been reported by ufuk (Ufuk Kayserilioglu). ---------------------------------------- Feature #19979: Allow methods to declare that they don't accept a block via `&nil` https://bugs.ruby-lang.org/issues/19979 * Author: ufuk (Ufuk Kayserilioglu) * Status: Open * Priority: Normal ---------------------------------------- ## Abstract This feature proposes new syntax to allow methods to explicitly declare that they don't accept blocks, and makes passing of a block to such methods an error. ## Background In #15554, it was proposed to automatically detect methods that do not use the block passed to them, and to error if a block was passed to such methods. As far as I can tell, it was later on closed since #10499 solved a large part of the problem. That proposal has, as part of the dev meeting discussion, a proposal from @matz to allow methods to use `&nil` to explicitly declare that they don't accept a block. At the time, the proposal was trying to solve a bigger problem, so this sub-proposal was never considered seriously. However, notes in the proposal say: > It is explicit, but it is tough to add this `&nil` parameter declaration to all of methods (do you want to add it to `def []=(i, e, &nil)`?). (I agree `&nil` is valuable on some situations) This proposal extracts that sub-proposal to make this a new language feature. ## Proposal In Ruby, it is always valid for the caller to pass a block to a method call, even if the callee is not expecting a block to be passed. This leads to subtle user errors, where the author of some code assumes a method call uses a block, but the block passed to the method call is silently ignored. The proposal is to introduce `&nil` at method declaration sites to mean "This method does not accept a block". This is symmetric to the ability to pass `&nil` at call sites to mean "I am not passing a block to this method call", which is sometimes useful when making `super` calls (since blocks are always implicitly passed). Explicitly, the proposal is to make the following behaviour be a part of Ruby: ```ruby def find(item = nil, &nil) # some implementation that doesn't call `yield` or `block_given?` end find { |i| i == 42 } # => ArgumentError: passing block to the method `find' that does not accept a block. ``` ## Implementation I assume the implementation would be a grammar change to make `&nil` valid at method declaration sites, as well as raising an `ArgumentError` for methods that are called with a block but are declared with `&nil`. ## Evaluation Since I don't have an implementation, I can't make a proper evaluation of the feature proposal. However, I would expect the language changes to be minimal with no runtime costs for methods that don't use the `&nil` syntax. ## Discussion This proposal has much smaller scope than #15554 so that the Ruby language can start giving library authors the ability to explicitly mark their methods as not accepting a block. This is fully backward compatible, since it is an opt-in behaviour and not an opt-out one. Future directions after this feature proposal could be a way to signal to the VM that any method in a file that doesn't explicitly use `yield`/`block_given?` or explicitly declared a block parameter should be treated as not accepting a block. This can be done via some kind of pragma similar to `frozen_string_literal`, or through other means. However, such future directions are beyond the scope of this proposal. ## Summary Adding the ability for methods to declare that they don't accept a block will make writing code against such methods safer and more resilient, and will prevent silently ignored behaviour that is often hard to catch or troubleshoot. -- https://bugs.ruby-lang.org/

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[ruby-core:123063] [Ruby Feature#21552] allow String.strip and similar to take a parameter similar to String.delete
by MSP-Greg (Greg L) 11 Dec '25

11 Dec '25

Issue #21552 has been reported by MSP-Greg (Greg L). ---------------------------------------- Feature #21552: allow String.strip and similar to take a parameter similar to String.delete https://bugs.ruby-lang.org/issues/21552 * Author: MSP-Greg (Greg L) * Status: Open ---------------------------------------- Regrading `String.strip` (and `lstrip`, `rstrip`, and `!` versions) Some text data representations differentiate between what one might call vertical and horizontal white space, and the 'strip' methods currently strip both. It would be helpful if they had an optional parameter similar to `String.delete` with a one multi-character selector, so one could do: ```ruby t = str.strip " \t" ``` One can use a regex for this, but this much simpler. -- https://bugs.ruby-lang.org/

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[ruby-core:122240] [Ruby Bug#21363] `Namespace.current` should always return the Namespace in which it was defined
by tenderlovemaking (Aaron Patterson) 09 Dec '25

09 Dec '25

Issue #21363 has been reported by tenderlovemaking (Aaron Patterson). ---------------------------------------- Bug #21363: `Namespace.current` should always return the Namespace in which it was defined https://bugs.ruby-lang.org/issues/21363 * Author: tenderlovemaking (Aaron Patterson) * Status: Open * ruby -v: ruby 3.5.0dev (2025-05-22T23:07:21Z rm-assertion 17e71c7a24) +PRISM [arm64-darwin24] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- I think `Namespace.current` should always return the namespace in which it was defined. Here is an example to demonstrate what I mean: ```ruby File.binwrite("ns.rb", <<-RUBY) # namespace 3 module M def self.test p Namespace.current end TEST = -> { p Namespace.current } end RUBY ns = Namespace.new ns.load "./ns.rb" p Namespace.current ns::M.test ns::M::TEST.call ``` I expect the output of `ns::M.test` and `ns::M::TEST.call` to be the same. Instead the output is like this: ``` #<Namespace:2,user,main> #<Namespace:3,user,optional> #<Namespace:2,user,main> ``` I think a method and lambda defined in the same namespace should return the same value for `Namespace.current` -- https://bugs.ruby-lang.org/

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[ruby-core:122114] [Ruby Bug#21341] `Namespace is not a module (TypeError)` without enabling the namespace
by yahonda (Yasuo Honda) 09 Dec '25

09 Dec '25

Issue #21341 has been reported by yahonda (Yasuo Honda). ---------------------------------------- Bug #21341: `Namespace is not a module (TypeError)` without enabling the namespace https://bugs.ruby-lang.org/issues/21341 * Author: yahonda (Yasuo Honda) * Status: Open * ruby -v: ruby 3.5.0dev (2025-05-15T08:25:56Z master 427ede2dde) +PRISM [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Ruby on Rails test case has the `module Namespace`. https://github.com/rails/rails/blob/main/activemodel/test/validators/namesp… ```ruby module Namespace class EmailValidator < ::EmailValidator end end ``` This code fails against Ruby 3.5.0dev without enabling the namespace feature. ### Steps to reproduce ```ruby $ ruby -ve 'module Namespace; end' ``` ### Expected behavior It should run without errors. ### Actual behavior It raises the TypeError. ```ruby $ ruby -ve 'module Namespace; end' ruby 3.5.0dev (2025-05-15T08:25:56Z master 427ede2dde) +PRISM [x86_64-linux] -e:1:in '<main>': Namespace is not a module (TypeError) ruby:0: previous definition of Namespace was here ``` Raising this TypeError with RUBY_NAMESPACE=1 looks expected to me. ```ruby $ RUBY_NAMESPACE=1 ruby -ve 'module Namespace; end' ruby 3.5.0dev (2025-05-15T08:25:56Z master 427ede2dde) +PRISM [x86_64-linux] ruby: warning: Namespace is experimental, and the behavior may change in the future! See doc/namespace.md for known issues, etc. -e:1:in '<main>': Namespace is not a module (TypeError) ruby:0: previous definition of Namespace was here ``` -- https://bugs.ruby-lang.org/

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[ruby-core:121955] [Ruby Bug#21320] Namespaces leak with constant lookup
by fxn (Xavier Noria) 09 Dec '25

09 Dec '25

Issue #21320 has been reported by fxn (Xavier Noria). ---------------------------------------- Bug #21320: Namespaces leak with constant lookup https://bugs.ruby-lang.org/issues/21320 * Author: fxn (Xavier Noria) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- The following program ```ruby X = :top class C X = :super end class D < C p X end ``` prints `:super` normally, and `:top` if running under a namespace. -- https://bugs.ruby-lang.org/

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