December 2024 - ruby-core - ml.ruby-lang.org

[ruby-core:117027] [Ruby master Bug#20319] Singleton class is being frozen lazily in some cases
by andrykonchin (Andrew Konchin) 24 Feb '26

24 Feb '26

Issue #20319 has been reported by andrykonchin (Andrew Konchin). ---------------------------------------- Bug #20319: Singleton class is being frozen lazily in some cases https://bugs.ruby-lang.org/issues/20319 * Author: andrykonchin (Andrew Konchin) * Status: Open * ruby -v: 3.2.2 * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I've noticed suspicious behaviour (it doesn't affect anything in practice for me though) when an object becomes frozen only its own singleton class becomes frozen immediately. A singleton class of the immediate singleton class becomes frozen lazily after `#singleton_class` method call: ```ruby o = Object.new klass = o.singleton_class.singleton_class o.freeze puts klass.frozen? # false <== here we expect true puts o.singleton_class.singleton_class.frozen? # true puts klass.frozen? # true ``` I would expect all created singleton classes in an object singleton classes chain to become frozen immediately. -- 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) 15 Feb '26

15 Feb '26

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:118784] [Ruby master Feature#20664] Add `before` and `until` options to Enumerator.produce
by knu (Akinori MUSHA) 08 Feb '26

08 Feb '26

Issue #20664 has been reported by knu (Akinori MUSHA). ---------------------------------------- Feature #20664: Add `before` and `until` options to Enumerator.produce https://bugs.ruby-lang.org/issues/20664 * Author: knu (Akinori MUSHA) * Status: Open ---------------------------------------- Enumerator.produce provides a nice way to generate an infinite sequence but is a bit awkward to define how to end a sequence. It lacks a simple and easy way to produce typical finite sequences in an intuitive syntax. This proposal attempts to solve the problem by adding these two options to the method: - `before`: when provided, it is used as a predicate to determine if an iteration should end before a generated value gets yielded. - `until`: when provided, it is used as a predicate to determine if an iteration should end until after a generated value gets yielded. Any value that responds to `to_proc` and returns a `Proc` object is accepted in these options. A typical use case for the `before` option is traversing a tree structure to iterate over the ancestors or following/preceding siblings of a node. The `until` option can be used when there is a clear definition of the "last" value to yield. ```ruby enum = Enumerator.produce(File, before: :nil?, &:superclass) enum.to_a #=> [File, IO, Object, BasicObject] enum = Enumerator.produce(3, until: :zero?, &:pred) enum_to_a #=> [3, 2, 1, 0] ``` ---Files-------------------------------- 0001-Add-before-and-until-options-to-Enumerator.produce.patch (10.7 KB) -- https://bugs.ruby-lang.org/

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[ruby-core:116028] [Ruby master Feature#20152] mkmf / extconf: Add a proper way to not compile the extension
by byroot (Jean Boussier) 06 Feb '26

06 Feb '26

Issue #20152 has been reported by byroot (Jean Boussier). ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d… - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e0… ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

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[ruby-core:116935] [Ruby master Bug#18743] Enumerator#next / peek re-use each others stacktraces
by nagachika (Tomoyuki Chikanaga) 22 Jan '26

22 Jan '26

Issue #18743 has been updated by nagachika (Tomoyuki Chikanaga). Backport changed from 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED to 3.0: REQUIRED, 3.1: REQUIRED, 3.2: DONE ruby_3_2 5e4606423da96c2e26b00981c22bddfce0d970bf merged revision(s) f15123c34ce80f3928612befe2a9aaf4c9d27fda. ---------------------------------------- Bug #18743: Enumerator#next / peek re-use each others stacktraces https://bugs.ruby-lang.org/issues/18743#change-106970 * Author: sos4nt (Stefan Schüßler) * Status: Closed * Assignee: ko1 (Koichi Sasada) * Backport: 3.0: REQUIRED, 3.1: REQUIRED, 3.2: DONE ---------------------------------------- I encountered an odd behavior. If I rescue the `StopIteration` exception from `peek` and call `next` afterwards: (or vice-versa) ```ruby # enum.rb # 1 # 2 enum = [].each # 3 enum.peek rescue nil # 4 enum.next # 5 ``` it will show the stacktrace from the rescued `peek` call: ``` $ ruby enum.rb enum.rb:4:in `peek': iteration reached an end (StopIteration) from enum.rb:4:in `<main>' ``` Whereas the error should refer to `next` on line number 5. The same happens when calling `peek` after `next` or when having muliple `peek` / `next` calls: ```ruby # enum.rb # 1 # 2 enum = [].each # 3 enum.peek rescue nil # 4 enum.next rescue nil # 5 enum.peek rescue nil # 6 puts "line #{__LINE__}" # 7 enum.next # 8 ``` The stacktrace from the first (rescued) `peek` or `next` call will be shown which doesn't reflect the actual error location: ``` $ ruby enum.rb line 7 enum.rb:4:in `peek': iteration reached an end (StopIteration) from enum.rb:4:in `<main>' ``` This is very confusing when debugging code. ---Files-------------------------------- 01-Recreate-stacktrace-enumerator.patch (1.29 KB) -- https://bugs.ruby-lang.org/

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[ruby-core:112045] [Ruby master Bug#19378] Windows: Use less syscalls for faster require of big gems
by aidog (Andi Idogawa) 12 Jan '26

12 Jan '26

Issue #19378 has been reported by aidog (Andi Idogawa). ---------------------------------------- Bug #19378: Windows: Use less syscalls for faster require of big gems https://bugs.ruby-lang.org/issues/19378 * Author: aidog (Andi Idogawa) * Status: Open * Priority: Normal * ruby -v: 3.2.0 * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN ---------------------------------------- Hello 🙂 ## Problem require is slow on windows for big gems. (example: require 'gtk3'=> 3 seconds+). This is a problem for people who want to make cross platform GUI apps with ruby. ## Possible Reason As touched on in [#15797](https://bugs.ruby-lang.org/issues/15797) it seems like require uses realpath, which is emulated on windows. It checks every parent directory. The same syscalls run many times. ## Testfile C:\tmp\speedtest\testrequire.rb: ``` ruby require __dir__ + "/helloworld1.rb" require __dir__ + "/helloworld2.rb" ``` ``` shell ruby --disable-gems C:\tmp\speedtest\testrequire.rb ``` ### Syscalls per File/Directory: 1. CreateFile 2. QueryInformationVolume 3. QueryIdInformation 4. QueryAllInformationFile 5. QueryNameInformationFile 6. QueryNameInformationFile 7. QueryNormalizedNameInformationFile 8. CloseFile ### Files/Directories checked 1. C:\tmp 2. C:\tmp\speedtest 3. C:\tmp\speedtest\helloworld1.rb 4. C:\tmp 5. C:\tmp\speedtest 6. C:\tmp\speedtest\helloworld2.rb For two required files Ruby had to do 8*6 = **48** syscalls. The syscalls orginate from rb_w32_reparse_symlink_p / lstat Rubygems live in subfolders with 9+ parts: "C:\Ruby32-x64\lib\ruby\gems\3.2.0\gems\glib2-4.0.8\lib\glib2\variant.rb" Each file takes 8 * 9 = **72**+ calls. For variant.rb it is **80** calls. The result for the syscalls don't change in such a short time, so it should be possible to cache it. With require_relative it's twice as many calls. ## Other testcases Same result: ``` ruby File.realpath __dir__ + "/helloworld1.rb" File.realpath __dir__ + "/helloworld2.rb" ``` ``` ruby File.stat __dir__ + "/helloworld1.rb" File.stat __dir__ + "/helloworld2.rb" ``` It does not happen in $LOAD_PATH.resolve_feature_path(__dir__ + "/helloworld1.rb") ## Request Would it be possible to cache the stat calls when using require? I tried to implement a cache inside the ruby source code, but failed. If not, is there now a way to combine ruby files into one? I previously talked about require here: [YJIT: Windows support lacking.](https://bugs.ruby-lang.org/issues/19325#note-11) ## How to reproduce Ruby versions: At least 3.0+, most likely older ones too. Tested using Ruby Installer 3.1 and 3.2. [Procmon Software by Sysinternals](https://learn.microsoft.com/en-us/sysinternals/downloads/proc… -- https://bugs.ruby-lang.org/

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[ruby-core:118957] [Ruby master Bug#20699] On Windows, the `__dir__` keyword is garbled in paths containing Japanese characters, and `require_relative` fails as well
by flatland001 (Hayato Arai) 18 Dec '25

18 Dec '25

Issue #20699 has been reported by flatland001 (Hayato Arai). ---------------------------------------- Bug #20699: On Windows, the `__dir__` keyword is garbled in paths containing Japanese characters, and `require_relative` fails as well https://bugs.ruby-lang.org/issues/20699 * Author: flatland001 (Hayato Arai) * Status: Open * ruby -v: ruby 3.3.4 (2024-07-09 revision be1089c8ec) [x64-mingw-ucrt] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- In paths containing Japanese characters, such as: C:\テスト_test\test.rb Code: ``` ruby # this code -> C:\テスト_test\test.rb # external file -> C:\テスト_test\lib\foo.rb p __dir__ p __dir__.encoding p File.dirname(File.expand_path(__FILE__)) p File.dirname(File.expand_path(__FILE__)).encoding print "__dir__ == File.dirname(File.expand_path(__FILE__)): " p __dir__ == File.dirname(File.expand_path(__FILE__)) begin require_relative "lib/foo" puts "foo.rb loaded" rescue LoadError puts "LoadError: #{$!}" end ``` Results: ``` "C:/?e?X?g_test" #<Encoding:Windows-31J> "C:/\x{8365}\x{8358}\x{8367}_test" #<Encoding:Windows-31J> __dir__ == File.dirname(File.expand_path(__FILE__)): false LoadError: cannot load such file -- C:/?e?X?g_test/lib/foo ``` However, in ruby 3.2.5 (2024-07-26 revision 31d0f1a2e7) [x64-mingw-ucrt], the same code produces the following expected results: ``` "C:/\x{8365}\x{8358}\x{8367}_test" #<Encoding:Windows-31J> "C:/\x{8365}\x{8358}\x{8367}_test" #<Encoding:Windows-31J> __dir__ == File.dirname(File.expand_path(__FILE__)): true foo.rb loaded ``` Is this behavior expected, or could this be a bug in the Ruby interpreter on Windows? If this is my misunderstanding or a known issue, I apologize. Thank you for your consideration. Environment Information: - OS: Windows 11 Pro 23H2 (OS build 22631.4037) - Installed via: RubyInstaller - Shell: Command Prompt - File System: NTFS - System Locale: Japanese (Japan), Language: Japanese -- https://bugs.ruby-lang.org/

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[ruby-core:120250] [Ruby master Feature#20953] Array#fetch_values vs #values_at protocols
by zverok (Victor Shepelev) 17 Dec '25

17 Dec '25

Issue #20953 has been reported by zverok (Victor Shepelev). ---------------------------------------- Feature #20953: Array#fetch_values vs #values_at protocols https://bugs.ruby-lang.org/issues/20953 * Author: zverok (Victor Shepelev) * Status: Open ---------------------------------------- I believe that the user might expect `#fetch_values` to be a stricter version of `#values_at`, confirming to the same protocol for arguments. But the current implementation for `#fetch_values` is simpler: ```ruby [1, 2, 3, 4, 5].values_at(0, 3..4) #=> [1, 4, 5] [1, 2, 3, 4, 5].fetch_values(0, 3..4) # TypeError: in 'Array#fetch': no implicit conversion of Range into Integer ``` I believe aligning the implementations would lessen confusion (even if it makes `#fetch_values` implementation somewhat less trivial). The practical example of usefulness: ```ruby HEADERS = %w[Name Department] def table_headers(rows) HEADERS.fetch_values(...rows.map(&:size).max) { '<unknown'> } # Or, alternatively: # HEADERS.fetch_values(...rows.map(&:size).max) { raise ArgumentError, "No header defined for column #{it + 1}" } end table_headers([ ['John'], ['Jane'], ]) #=> ["Name"] table_headers([ ['John'], ['Jane', 'Engineering'], ]) #=> ["Name", "Department"] table_headers([ ['John', 'Accounting', 'Feb 24'], ['Jane', 'Engineering'], ]) #=> ["Name", "Department", "<unknown>"] # or ArgumentError No header defined for column 3 ``` (Obviously, we can use `fetch_values(*(0...max_row_size))` as an argument, but it feels like an unjustified extra work when `values_at` already can do this.) -- 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) 12 Dec '25

12 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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