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

[ruby-core:122411] [Ruby Bug#21396] Set#initialize should call Set#add on items passed in
by tenderlovemaking (Aaron Patterson) 17 Nov '25

17 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) 16 Nov '25

16 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 13 Nov '25

13 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:122773] [Ruby Feature#21513] Raise on converting endless range to set
by viralpraxis (Iaroslav Kurbatov) 13 Nov '25

13 Nov '25

Issue #21513 has been reported by viralpraxis (Iaroslav Kurbatov). ---------------------------------------- Feature #21513: Raise on converting endless range to set https://bugs.ruby-lang.org/issues/21513 * Author: viralpraxis (Iaroslav Kurbatov) * Status: Open ---------------------------------------- Converting endless range to array raises: ``` shell ruby -e '(1..).to_a' -e:1:in 'Range#to_a': cannot convert endless range to an array (RangeError) from -e:1:in '<main>' ``` but converting to set does not: ``` shell ruby -e '(1..).to_set # hangs' ``` I think it makes to raise in both cases for consistency. Something like this should do the trick: ``` diff diff --git i/prelude.rb w/prelude.rb index f49cada637..11bfa3fc95 100644 --- i/prelude.rb +++ w/prelude.rb @@ -30,6 +30,10 @@ module Enumerable # Makes a set from the enumerable object with given arguments. # Passing arguments to this method is deprecated. def to_set(*args, &block) + if self.class == Range && self.end.nil? + raise RangeError, "cannot convert endless range to a set" + end + klass = if args.empty? Set else diff --git i/test/ruby/test_range.rb w/test/ruby/test_range.rb index f875c0ab40..27b968641b 100644 --- i/test/ruby/test_range.rb +++ w/test/ruby/test_range.rb @@ -1541,4 +1541,11 @@ def test_overlap? assert_not_operator((1...3), :overlap?, (3..4)) assert_not_operator((...3), :overlap?, (3..)) end + + def test_to_set + assert_equal(Set[], (1..-1).to_set) + assert_equal(Set[1, 2, 3], (1..3).to_set) + + assert_raise(RangeError) { (239..).to_set } + end end ``` If this patch is accepted, I'll open a PR. ``` shell ./ruby -v ruby 3.5.0dev (2025-07-14T20:34:32Z master a6d483971a) +PRISM [x86_64-linux] ``` -- https://bugs.ruby-lang.org/

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[ruby-core:122343] [Ruby Misc#21385] Namespace: Suggesting a rename
by fxn (Xavier Noria) 10 Nov '25

10 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:123146] [Ruby Bug#21559] Unicode normalization nfd -> nfc -> nfd is not reversible
by tompng (tomoya ishida) 02 Nov '25

02 Nov '25

Issue #21559 has been reported by tompng (tomoya ishida). ---------------------------------------- Bug #21559: Unicode normalization nfd -> nfc -> nfd is not reversible https://bugs.ruby-lang.org/issues/21559 * Author: tompng (tomoya ishida) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- I expect `nfd(nfc(str)) == nfd(str)` but found a string that doesn't. ~~~ruby # Ruby 3.1 - 3.5 str = "s\u{11930}\u{323}\u{11930}\u{307}" p str.unicode_normalize(:nfd) == str.unicode_normalize(:nfc).unicode_normalize(:nfd) #=> false ~~~ ~~~ruby # ruby 3.5.0dev str = "s\u{1611e}\u{323}\u{1611e}\u{307}\u{1611f}" p str.unicode_normalize(:nfd) == str.unicode_normalize(:nfc).unicode_normalize(:nfd) #=> false ~~~ -- https://bugs.ruby-lang.org/

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[ruby-core:123172] [Ruby Bug#21560] RUBY_MN_THREADS=1 causes large performance regression in Puma 7
by schneems (Richard Schneeman) 01 Nov '25

01 Nov '25

Issue #21560 has been reported by schneems (Richard Schneeman). ---------------------------------------- Bug #21560: RUBY_MN_THREADS=1 causes large performance regression in Puma 7 https://bugs.ruby-lang.org/issues/21560 * Author: schneems (Richard Schneeman) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ## Expected Running a webserver with `RUBY_MN_THREADS=1` will increase performance or keep it the same. ## Actual - Before: 22919.85 Requests/sec - After: 2287.13 Requests/sec ## Reproduction Tracking this at https://github.com/puma/puma/issues/3720. I would like to get a smaller reproduction, but until then here's how we're able to induce the failure: Prepare puma: ``` $ git clone https://github.com/puma/puma $ cd puma $ git checkout v7.0.0.pre1 $ rake compile ``` Boot the server to deliver a "hello world" response: ``` $ bundle exec ruby -Ilib bin/puma -w 1 -t1 --preload test/rackup/hello.ru ``` Exercise the server with `wrk` (brew install wrk): ``` $ wrk -H 'Host: tfb-server' -H 'Accept: text/plain,text/html;q=0.9,application/xhtml+xml;q=0.9,application/xml;q=0.8,*/*;q=0.7' -H 'Connection: keep-alive' --latency -d 15 -c 16 --timeout 8 -t 12 http://localhost:9292 ``` ### Results Before: ``` $ bundle exec ruby -Ilib bin/puma -w 1 -t1 --preload test/rackup/hello.ru ``` ``` $ wrk -H 'Host: tfb-server' -H 'Accept: text/plain,text/html;q=0.9,application/xhtml+xml;q=0.9,application/xml;q=0.8,*/*;q=0.7' -H 'Connection: keep-alive' --latency -d 15 -c 16 --timeout 8 -t 12 http://localhost:9292 Running 15s test @ http://localhost:9292 12 threads and 16 connections Thread Stats Avg Stdev Max +/- Stdev Latency 786.74us 1.45ms 45.57ms 90.62% Req/Sec 1.92k 188.55 4.20k 83.22% Latency Distribution 50% 386.00us 75% 523.00us 90% 2.11ms 99% 4.63ms 344638 requests in 15.04s, 25.23MB read Requests/sec: 22919.85 Transfer/sec: 1.68MB ``` After: ``` $ env RUBY_MN_THREADS=1 bundle exec ruby -Ilib bin/puma -w 1 -t1 --preload test/rackup/hello.ru ``` ``` $ wrk -H 'Host: tfb-server' -H 'Accept: text/plain,text/html;q=0.9,application/xhtml+xml;q=0.9,application/xml;q=0.8,*/*;q=0.7' -H 'Connection: keep-alive' --latency -d 15 -c 16 --timeout 8 -t 12 http://localhost:9292 Running 15s test @ http://localhost:9292 12 threads and 16 connections Thread Stats Avg Stdev Max +/- Stdev Latency 28.89ms 40.82ms 129.37ms 78.94% Req/Sec 207.34 64.09 252.00 70.70% Latency Distribution 50% 212.00us 75% 56.77ms 90% 99.48ms 99% 127.01ms 34365 requests in 15.03s, 2.52MB read Requests/sec: 2287.13 Transfer/sec: 171.45KB ``` (Notice the dramatic drop in requests per second). -- https://bugs.ruby-lang.org/

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[ruby-core:123350] [Ruby Bug#21618] Allow to use the build-in prism version to parse code
by Earlopain (Earlopain _) 29 Oct '25

29 Oct '25

Issue #21618 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21618: Allow to use the build-in prism version to parse code https://bugs.ruby-lang.org/issues/21618 * Author: Earlopain (Earlopain _) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Prism is a multi-version parser, which is a great feature. If one calls `Prism.parse("foo")`, it will always use the latest version prism knows about. This may or may not be the version that is currently executing. This is problematic when one wants to introspect code the same way that the currently running ruby version would. Consider that some syntax will be disallowed in the next ruby version. I would have to specify the ruby version I want to parse as in order to not run into syntax errors: `Prism.parse("foo", version: RUBY_VERSION)`. But doing so is not feasable because `prism` is distributed out of sync with ruby itself. If the user already has prism in their lockfile, the user may run a prism version that doesn't yet know about lets say ruby 4.0 and thus raise. Similarly, it may parse as an older patch version that has subtle behaviour differences. `ripper` does not have this issue because it is always tied to the ruby version and it is not distributed as a gem, so what the user has will always be exactly what ruby shipped with. I wish for a similar API that utilizes the prism version bundled with ruby itself. Libraries like `rails` have moved from ripper to prism because of its superior developer experience but it risks breaking in unexpected ways with new `prism` versions that know about more recent syntax. `error_highlight` for example also suffers from the same defect. It seems like prism currently has 34 methods that optionally take a version (per the rbi file). Many of these are trivial helper methods like `Prism.parse_success?` (does the parse result have any errors?). I would be happy with supporting only the minimal functions like `Prism.parse` and `Prism.parse_file`. Currently I don't have a use-case for any of the other methods. Pretty much just functions to mirror `RubyVM::InstructionSequence.compile_file` and `RubyVM::InstructionSequence.compile`. It would be optimal if I would be able to transparently call `Prism.parse("foo", version: "current")` (or maybe even have an unspecified version mean the build-in prism version) but I am not sure how feasable that is since I'm pretty sure logic for this would have to live in ruby itself. @kddnewton does this feature request make sense? Do you have any other ideas/inputs? -- https://bugs.ruby-lang.org/

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