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

[ruby-core:124887] [Ruby Bug#21926] Thread#value on popen3 wait thread hangs in finalizer
by stevecrozz (Stephen Crosby) 05 Mar '26

05 Mar '26

Issue #21926 has been reported by stevecrozz (Stephen Crosby). ---------------------------------------- Bug #21926: Thread#value on popen3 wait thread hangs in finalizer https://bugs.ruby-lang.org/issues/21926 * Author: stevecrozz (Stephen Crosby) * Status: Open * ruby -v: 3.3.7 * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- Calling Thread#value on an Open3.popen3 wait thread from a finalizer completes in Ruby 3.2 but hangs in Ruby 3.3+. See repro.rb below. When the Ruby process hangs in these conditions, it no longer responds to signals and it seems to be unable to run any other threads. This affects the schmooze gem (and potentially other code using Open3.popen3 with finalizers), causing test suites to hang intermittently. ``` ruby # repro.rb require 'open3' class ProcessWrapper def initialize @stdin, @stdout, @stderr, @wait_thread = Open3.popen3("cat") ObjectSpace.define_finalizer(self, self.class.make_finalizer(@stdin, @stdout, @stderr, @wait_thread)) end def self.make_finalizer(stdin, stdout, stderr, wait_thread) proc do stdin.close rescue nil stdout.close rescue nil stderr.close rescue nil wait_thread.value # Hangs here in Ruby 3.3+ end end end 100.times { ProcessWrapper.new } GC.stress = true 1000.times { Object.new } puts "done" ``` ## Environment - Linux x86_64 - Tested on Ruby 3.2.7, 3.3.7, 3.4.8 -- https://bugs.ruby-lang.org/

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[ruby-core:123672] [Ruby Feature#21665] Revisit Object#deep_freeze to support non-Ractor use cases
by headius (Charles Nutter) 05 Mar '26

05 Mar '26

Issue #21665 has been reported by headius (Charles Nutter). ---------------------------------------- Feature #21665: Revisit Object#deep_freeze to support non-Ractor use cases https://bugs.ruby-lang.org/issues/21665 * Author: headius (Charles Nutter) * Status: Open ---------------------------------------- ## Proposal: Introduce `Object#deep_freeze` (or similar name) to freeze an entire object graph I would like to re-propose the addition of Object#deep_freeze as a way to explicitly freeze an entire object graph. This proposal was rejected some years ago after being brought up in https://bugs.ruby-lang.org/issues/17145. The proposal was rejected in favor of making Ractor-specific methods like Ractor.make_shareable. There are a number of reasons why I believe `deep_freeze` is still an important addition: * Rubyists have been requesting a way to deep freeze an object graph for many years (decades?), far longer than Ractor has existed. * Immutable objects are the safest way to safe concurrency, with or without parallel threading or Ractor. * In fact, deep freezing has utility *completely unrelated to concurrency*, such as to guarantee that a large graph of objects will not be modified in the future. * In the absence of `deep_freeze`, users have been forced to implement the behavior themselves, rely on third-party libraries, or call `Ractor.make_shareable` even if they never intend to use Ractor. * The existing `Ractor.make_shareable` primarily does a deep freeze internally. Given the steady move toward making immutability the norm in Ruby, it seems clear to me that deep freezing is a feature that is long overdue. ## Revisiting arguments for rejecting `deep_freeze`: A number of reasons were given in #17145 for preferring the `Ractor.make_shareable` method and rejecting `deep_freeze`. I address those here: @ko1: > One concern about the name "freeze" is, what happens on shareable objects on Ractors. > For example, Ractor objects are shareable and they don't need to freeze to send beyond Ractor boundary. As mentioned above, deep freezing has utility completely separate from Ractors and concurrency. It is a frequently-requested and very useful feature to add. I think we should treat this as a standalone feature, and treat enhancements for Ractors as a separate concern. @ko1: > I also want to introduce Mutable but shareable objects using STM (or something similar) writing protocol (shareable Hash). What happens on deep_freeze? Five years later, I believe this has not yet happened. A potential future optimization for Ractor should not be justification to reject a useful feature today. If users implement their code using primarily immutable objects now, it's unlikely that they will want those same objects to be mutable in the future (this applies to deep freezing as well as `make_shareable`). @eregon: > A dynamic call to freeze causes extra calls, and needs checks that it was indeed frozen. > So for efficiency I think it would be better to mark as frozen internally without a call to freeze on every value. I agree with the concerns about dynamic calls to freeze and overridden versions of the method. It may make more sense to implement this as a utility method, like `Object.deep_freeze(obj)` (a non-overridable class utility method). This is essentially what has been implemented within `Ractor.make_shareable` today. @ko1: > Maybe the author don't want to care about Ractor. > The author want to declare "I don't touch it". So "deep_freeze" is better. This was actually given as a justification for a `deep_freeze` method versus something like `Object#to_shareable`, and yet what we ended up with was a method that requires users know about Ractor. I believe there should be a `deep_freeze` method that has nothing to do with Ractor. And users on JRuby and TruffleRuby already can get full parallelism today without Ractor. They do not care about Ractor, but they definitely care about deep freezing. @eregon: > I don't like anything with "ractor" in the name, that becomes not descriptive of what it does and IMHO looks weird for e.g. gems not specifically caring about Ractor. This is a large part of my justification for revisiting this proposal. Users should not have to care about or want to use Ractor just so they can deep freeze an object graph, because it has utility far beyond Ractor. @ko1: > I implemented Object#deep_freeze(skip_shareable: false) for trial. > https://github.com/ko1/ruby/pull/new/deep_freeze There's already a prototype of this, though I suspect this logic essentially became `Ractor.make_shareable` in the end. I believe it would be acceptable to implement `Ractor.make_shareable` by calling `deep_freeze` since there's largely no difference in visible behavior (other than Ractor-specific optimizations like marking a whole graph as shareable). @eregon: > How about first having deep_freeze that just freezes everything (except an object's class)? This is a good proposal. I believe it is what 99% of users currently calling `make_shareable` actually want, and again there's utility well beyond Ractor and concurrency scenarios. @eregon: > So we could mark as deeply frozen first, and remember to undo that if we cannot freeze some object. > However, is there any object that cannot be frozen? I would think not. The majority of uses of `make_shareable` I have seen are called exactly once on a graph of objects. It does not seem to be typical to repeatedly call `make_shareable`. I understand the desire to have a `shareable` bit for Ractor optimization, but that is a *separate feature* from deep freezing an object graph. There are many cases where we will only call `deep_freeze` once to ensure a graph is fully frozen before publishing it for other code to see, and most of these cases will not try to re-deep-freeze that graph. Ractor's need to "double-check" shareability is orthogonal to the discussion about deep freezing and should not be justification for rejecting `deep_freeze`. @eregon brought up concerns about not calling the custom `freeze` method on user types, since they may want to eagerly cache some data. I believe that discussion is out of scope. `deep_freeze` would be defined to only free the objects that are directly walkable from a root object, and only setting frozen bits. A new overridable method could be introduced that `deep_freeze` would call if present, but otherwise it should just do fast-path object freeze flag setting. @marcandre: > Looking at def freeze in the top ~400 gems, I found 64 in sequel gem alone, and 28 definitions in the rest 😅. This comment provides a breakdown of custom `freeze` methods and the reasons they are implemented. Again, I believe this is out of scope for the discussion at hand. Forcing objects to "prepare for deep freezing" is a separate consideration that will be very library-specific, since every library may want to prepare in a different way. But they *all* want the ability to recursively mark objects as frozen, which is a runtime-level feature. @ko1: > We discussed about the name "deep_freeze", and Matz said deep_freeze should be only for freezing, not related to Ractor. So classes/module should be frozen if [C].deep_freeze. This is why I proposed a Object#deep_freeze(skip_shareable: true) and Ractor.make_shareable(obj). Avoiding classes and modules when deep freezing seems like a reasonable option to me. Naming could make this behavior clear, but again I believe 99% of users just want a plain old object `deep_freeze`. And this is again conflating two separate concerns: * deep freezing * marking an entire graph as shareable These are – and should be – two separate features. The deep freezing feature should not depend on setting shareability bits, since shareability is only meaningful in the context of Ractors. @ko1: > So naming issue is reamained? > > Object#deep_freeze (matz doesn't like it) > Object#deep_freeze(skip_sharable: true) (I don't know how Matz feel. And it is difficult to define Class/Module/... on skip_sharable: false) > Ractor.make_shareable(obj) (clear for me, but it is a bit long) > Ractor.shareable!(obj) (shorter. is it clear?) > Object#shareable! (is it acceptable?) > ... other ideas? I outline some alternatives below. ## Alternative forms: @matz didn't like `deep_freeze` five years ago. How do you feel about it now, @matz? Some alternatives with justification: * Object.deep_freeze(obj) This would make sense to avoid users being able to override the `deep_freeze` behavior, and would make it feel more like a global utility method with special behavior. * Object#freeze(obj, deep: true) * Object#freeze(obj, recursive: true) These work within the existing `freeze` method and still convey intent, but may break APIs that don't expect to receive keyword arguments. And there are some alternative names, which may work as either instance methods or class methods: * `freeze_recursive` * `freeze_all` * `freeze!` * `freeze_reachable_objects` (long but a variation of this might address concerns about not freezing classes and modules) -- https://bugs.ruby-lang.org/

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[ruby-core:124714] [Ruby Bug#21870] Regexp: Warnings when using multiple non-overlapping \p{...} classes
by jneen (Jeanine Adkisson) 05 Mar '26

05 Mar '26

Issue #21870 has been reported by jneen (Jeanine Adkisson). ---------------------------------------- Bug #21870: Regexp: Warnings when using multiple non-overlapping \p{...} classes https://bugs.ruby-lang.org/issues/21870 * Author: jneen (Jeanine Adkisson) * Status: Open * ruby -v: 4.0.0, 4.0.1, earlier versions to a lesser extent * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ```ruby $VERBOSE = true # warning: character class has duplicated range: /[\p{Word}\p{S}]/ regex = /[\p{Word}\p{S}]/ ``` As far as I can tell this is a perfectly valid and non-overlapping set of unicode properties, but I am still being spammed with warnings. Using `/(\p{Word}|\p{S})/` is kind of a workaround, but it is slower. -- https://bugs.ruby-lang.org/

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[ruby-core:124419] [Ruby Bug#21827] Deprecating Ripper
by Eregon (Benoit Daloze) 03 Mar '26

03 Mar '26

Issue #21827 has been reported by Eregon (Benoit Daloze). ---------------------------------------- Bug #21827: Deprecating Ripper https://bugs.ruby-lang.org/issues/21827 * Author: Eregon (Benoit Daloze) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- I think it is time to consider deprecating `Ripper`. [Matz has agreed that going forward the official parser API for Ruby will be the Prism API](https://railsatscale.com/2024-04-16-prism-in-2024/) so it's clear the official Ruby parsing API is the Prism API. `Ripper` while being currently supported on CRuby, JRuby and TruffleRuby (partially) has a significant maintenance overhead. For CRuby, it roughly doubles the number of lines in `parse.y` and adds lots of `#ifdef RIPPER`/`#ifndef RIPPER` which makes it really hard to follow. For JRuby it's many thousands of lines of code to maintain just for that: https://github.com/jruby/jruby/tree/master/core/src/main/java/org/jruby/ext… For TruffleRuby, `ripper` is by far the most difficult C extension to support as it relies on many internal functions. When an internal function is used by ripper is missing it kills the entire process. On every update of `RUBY_VERSION` in TruffleRuby, the biggest amount of time is spent dealing with Ripper, which feels as a result like a major hack. It could be possible to implement Ripper based on Prism, in fact there is [some support for that](https://github.com/ruby/prism/blob/main/docs/ripper_translation.md), but the fact the Ripper API is rather unstable means it's hard to be compatible, and currently the translation layer [relies on original ripper for some things](https://github.com/ruby/prism/blob/e0e5e68acbed98a6b4e4e77b9b52b448…. It's also worth noting that [`Ripper.sexp` is 2.75x slower than `Prism.parse`](https://eregon.me/blog/2024/10/27/benchmarking-ruby-parsers.html#parsing-and-not-walking), while providing a much worse API (widely recognized as such, e.g. `Ripper.sexp("def m = 42")` vs `Prism.parse("def m = 42")`, lots of `nil` with unclear meaning in `Ripper`). So from a new code perspective there seems to be very little value to use `Ripper`. `Ripper` has lexing via `Ripper.lex`, which can be replaced by `Prism::lex_compat`. I think we should start to deprecate `Ripper`. The advantages of deprecating it are: * Make it clear that this API should not be used in new code * Encourage the usages to migrate to the Prism API, which is stable, officially supported, designed with many people to be usable and convenient for every parsing/tooling usage, etc. * Improve portability of Ruby code between Ruby implementations (given Ripper is not fully compatible between Ruby implementations) I propose to deprecate Ripper in 4.1. I'm not sure when it would be appropriate to remove it given it's a more established API, maybe in 4.2, 4.3? -- https://bugs.ruby-lang.org/

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[ruby-core:124891] [Ruby Misc#21928] Prism backport handling
by Earlopain (Earlopain _) 03 Mar '26

03 Mar '26

Issue #21928 has been reported by Earlopain (Earlopain _). ---------------------------------------- Misc #21928: Prism backport handling https://bugs.ruby-lang.org/issues/21928 * Author: Earlopain (Earlopain _) * Status: Open * Assignee: prism ---------------------------------------- https://bugs.ruby-lang.org/issues/21927 got marked for backport for 4.0 and 3.4. It's a trivial fix but since prism is a gem, ruby should contain a released version of prism only. 3.4 in particular currently contains prism 1.5.2. Backporting to that version would require at least two changes in `ruby/ruby` because of changes in prism itself. So it is not as easy as just `tool/sync_default_gems`. Currently the practise has been to just backport the lastest prism version but personally I don't think that is sustainable. At best it causes more work than necessary and at worst you get fresh new bugs in what is supposed to be a stable ruby release. https://github.com/ruby/prism/pull/3231 is a good example of something that should not be backported to all maintained ruby versions when it gets merged. I propose to maintain stable branches for prism. Branch maintainers can simply cherry-pick what they think should be backported and prism takes care of releasing the appropriate versions, branched from the version that the stable ruby version originally shipped with. As far as I'm aware, that's also the strategy other gems go with. It happens less frequent now that many gems are no longer standard gems but openssl for example has branches for this purpose https://github.com/ruby/openssl/branches. I'm not sure how it handles versions, some gems I see do `1.2.3.4` which doesn't exactly follow semver, but it should possible to do it by following semver. What do you think @kddnewton? I know that so far you've wanted to do the latest stable version but I think prism is too intertwined with ruby itself for the current approach. Especially now that there are two stable branches that ship with prism it doesn't get easier. -- https://bugs.ruby-lang.org/

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[ruby-core:124885] [Ruby Bug#21925] Prism misparses standalone "in" pattern matching in "case/in"
by knu (Akinori MUSHA) 02 Mar '26

02 Mar '26

Issue #21925 has been reported by knu (Akinori MUSHA). ---------------------------------------- Bug #21925: Prism misparses standalone "in" pattern matching in "case/in" https://bugs.ruby-lang.org/issues/21925 * Author: knu (Akinori MUSHA) * Status: Open * Target version: 4.1 * ruby -v: ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [arm64-darwin23] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- Prism misparses standalone `in` pattern matching in `case/in` when the left-hand side is a method call with a dot receiver ## Summary When a standalone `expr in pattern` one-line pattern match appears inside a `case/in` branch, and `expr` is a method call with a dot receiver (for example, `obj.method`), Prism incorrectly parses `in pattern` as a new branch of the outer `case/in` instead of treating it as a `MatchPredicateNode`. The parse.y parser handles this case correctly. ## Reproduction ``` $ ruby -v ruby 4.0.1 (2026-01-13 revision e04267a14b) +PRISM [arm64-darwin23] ``` It also reproduces on Ruby 3.4.8 (2025-12-17 revision 995b59f666) +PRISM [arm64-darwin25]. ### Minimal script ```ruby x = "x" case x in Integer nil in String p :before x.itself in String p :after end ``` ### Command output ``` $ ruby -e ' x = "x" case x in Integer nil in String p :before x.itself in String p :after end ' :before $ ruby --parser=parse.y -e ' x = "x" case x in Integer nil in String p :before x.itself in String p :after end ' :before :after ``` ### Expected behavior (parse.y) Both `:before` and `:after` are printed. `x.itself in String` is parsed as a standalone pattern match (predicate) inside the `in String` branch. ### Actual behavior (Prism) Only `:before` is printed; `p :after` is never executed. ## Analysis Prism splits `x.itself in String` at the `in` keyword, treating `x.itself` as the last statement of the `in String` branch and `in String` as a third branch of the outer `case/in`. The following script shows how each parser interprets the `case/in` branches: ```ruby code = <<~RUBY x = "x" case x in Integer nil in String x.itself in String p :after end RUBY # Prism require "prism" ast = Prism.parse(code).value.statements.body[1] puts "Prism: conditions: #{ast.conditions.length}" ast.conditions.each_with_index do |c, i| pat = c.pattern name = pat.respond_to?(:name) ? pat.name : pat.class stmts = c.statements&.body&.map { |s| s.class.name.split("::").last } || [] puts " in[#{i}]: pattern=#{name}, body=#{stmts}" end # parse.y (Ripper) require "ripper" sexp = Ripper.sexp(code) case_node = sexp[1][1] def count_in_branches(node) return [] unless node.is_a?(Array) && node[0] == :in pattern_node = node[1] body = node[2] || [] name = pattern_node.is_a?(Array) && pattern_node[1].is_a?(Array) ? pattern_node[1][1] : pattern_node[1] stmts = body.map { |s| s[0].to_s } [{ pattern: name, body: stmts }] + count_in_branches(node[3]) end branches = count_in_branches(case_node[2]) puts "\nparse.y (Ripper): conditions: #{branches.length}" branches.each_with_index do |b, i| puts " in[#{i}]: pattern=#{b[:pattern]}, body=#{b[:body]}" end ``` Output (run with `ruby --parser=parse.y` so Ripper uses parse.y): ``` Prism: conditions: 3 in[0]: pattern=Integer, body=["NilNode"] in[1]: pattern=String, body=["CallNode"] in[2]: pattern=String, body=["CallNode"] parse.y (Ripper): conditions: 2 in[0]: pattern=Integer, body=["var_ref"] in[1]: pattern=String, body=["case", "command"] ``` Prism reports 3 branches, while parse.y reports 2. In the parse.y result, `in[1]` correctly contains both the inner expression (`x.itself in String` parsed as a standalone pattern match) and the `command` (`p :after`). In the Prism result, `x.itself` becomes the sole body of `in[1]`, and `in String` is misinterpreted as a new `in[2]` branch of the outer `case`. ## Consideration From experimentation, the issue appears to be triggered only when all of the following are true: 1. The outer `case/in` has at least two `in` branches before the affected branch. 2. The standalone `in` expression uses a dot-receiver method call as its left-hand side, such as `obj.method in Pattern`. Conditions where this behavior is not observed: - If the expression is a receiver-less call, such as `f(x) in Pattern`, the parser keeps it as a standalone pattern match. - If the receiver expression is parenthesized, such as `(obj.method) in Pattern`, the parser keeps it as a standalone pattern match. - If you assign first, such as `y = obj.method; y in Pattern`, the parser keeps it as a standalone pattern match. -- https://bugs.ruby-lang.org/

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[ruby-core:124797] [Ruby Feature#21875] Handling of trailing commas in lambda parameters
by Earlopain (Earlopain _) 01 Mar '26

01 Mar '26

Issue #21875 has been reported by Earlopain (Earlopain _). ---------------------------------------- Feature #21875: Handling of trailing commas in lambda parameters https://bugs.ruby-lang.org/issues/21875 * Author: Earlopain (Earlopain _) * Status: Open ---------------------------------------- https://bugs.ruby-lang.org/issues/19107 was accepted, which is about trailing commands in method definitions. lambdas were not explicitly mentioned but I wanted to confirm how they should behave with a trailing comma. Or if a trailing comma should even be accepted for them. It's not clear to me since lambdas sometimes behave like blocks and sometimes more like methods. `->(...) {}` for example is syntax invalid (same as in blocks) but they do check their arity with blocks don't do. If a trailing comma is accepted it can either * be implicit splat like in `foo do |bar,|; end` or `foo do |bar|; end`. It would also mean that the trailing comma is only allowed after a positional argument. * Just be ignored and be accepted in most places like for method definitions. The first option would be rather useless in regards to https://bugs.ruby-lang.org/issues/19107 when you just want to add the comma for cleaner diffs. But I guess for lambdas this happens very rarely anyways. -- https://bugs.ruby-lang.org/

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[ruby-core:124892] [Ruby Feature#21929] Add configure script options for instrumenting Rust builds
by jprokop (Jarek Prokop) 27 Feb '26

27 Feb '26

Issue #21929 has been reported by jprokop (Jarek Prokop). ---------------------------------------- Feature #21929: Add configure script options for instrumenting Rust builds https://bugs.ruby-lang.org/issues/21929 * Author: jprokop (Jarek Prokop) * Status: Open ---------------------------------------- Ruby at this moment optionally includes Rust bits. Right now this touches mostly YJIT and ZJIT. Rust is a compiled language with various compile flags at various stages and approaches. My ask is to provide a way to instrument compilation similarly as with C at the moment so that packagers and distributions can be fully and easily compliant with their guidelines on compilation flags. Currently, for production build of Ruby, `rustc` tool is used, which is instrumented differently from `cargo` in debug builds. In my PR motivated by the described goal: https://github.com/ruby/ruby/pull/15695 I have focused on providing `rustc` with our distribution flags, during the PR it was mentioned that there are flags related to security https://github.com/ruby/ruby/pull/15695#discussion_r2663651764 that should be present even when providing distribution flags. This is not too different from C, as there are also security flags, such as configure script enabling the arm64's BTI and PAC when possible. `rustc` of version 1.92, at the time of the PR uses the last mention of a flag. Ideally `rustc` would know `RUSTFLAGS`, but as far as I can tell, the enviroment variable only affects `cargo`. In Fedora the current guidance recommends using `%build_rustflags` https://docs.fedoraproject.org/en-US/packaging-guidelines/Rust/#_compiler_f… which expands to `-Copt-level=3 -Cdebuginfo=2 -Ccodegen-units=1 -Cstrip=none -Cforce-frame-pointers=yes --cap-lints=warn` The best result is each part of Rust in Ruby would receive the flags defined during `configure` time. In cases where complication flags should conflict, in Fedora distribution flags take precedence: https://docs.fedoraproject.org/en-US/packaging-guidelines/Rust/#_building_w… -- https://bugs.ruby-lang.org/

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[ruby-core:124888] [Ruby Bug#21927] Prism: misleading error message for forwarding in lambda argument
by nobu (Nobuyoshi Nakada) 27 Feb '26

27 Feb '26

Issue #21927 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21927: Prism: misleading error message for forwarding in lambda argument https://bugs.ruby-lang.org/issues/21927 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Assignee: prism * ruby -v: d256629bf9 * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED, 4.0: REQUIRED ---------------------------------------- Even in a forwarding method: ```console $ ruby --parser=prism -e 'def m(...) ->(...){}; end' -e: -e:1: syntax error found (SyntaxError) > 1 | def m(...) ->(...){}; end | ^~~ unexpected ... when the parent method is not forwarding ``` This message is proper for method arguments: ```console $ ruby --parser=prism -e 'def m() p(...); end' -e: -e:1: syntax error found (SyntaxError) > 1 | def m() p(...); end | ^~~ unexpected ... when the parent method is not forwarding ``` The message from parse.y is different; "unexpected ... in lambda argument": ```console $ ruby --parser=parse.y -e 'def m(...) ->(...){}; end' -e:1: unexpected ... in lambda argument def m(...) ->(...){}; end ruby: compile error (SyntaxError) ``` -- https://bugs.ruby-lang.org/

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[ruby-core:123894] [Ruby Bug#21709] Inconsistent encoding by Regexp.escape
by thyresias (Thierry Lambert) 26 Feb '26

26 Feb '26

Issue #21709 has been reported by thyresias (Thierry Lambert). ---------------------------------------- Bug #21709: Inconsistent encoding by Regexp.escape https://bugs.ruby-lang.org/issues/21709 * Author: thyresias (Thierry Lambert) * Status: Open * ruby -v: ruby 3.4.7 (2025-10-08 revision 7a5688e2a2) +PRISM [x64-mingw-ucrt] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```ruby %w(foo être).each do |s| puts "string: #{s.inspect} -> #{s.encoding}" puts "escaped: #{Regexp.escape(s).inspect} -> #{Regexp.escape(s).encoding}" end ``` Output: ``` string: "foo" -> UTF-8 escaped: "foo" -> US-ASCII string: "être" -> UTF-8 escaped: "être" -> UTF-8 ``` The result should always match the encoding of the argument. -- https://bugs.ruby-lang.org/

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