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

[ruby-core:122343] [Ruby Misc#21385] Namespace: Suggesting a rename
by fxn (Xavier Noria) 20 Sep '25

20 Sep '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/

17 28

[ruby-core:121234] [Ruby master Bug#21168] Prism doesn't require argument parentheses (in some cases) when a block is present but parse.y does
by Earlopain (Earlopain _) 19 Sep '25

19 Sep '25

Issue #21168 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21168: Prism doesn't require argument parentheses (in some cases) when a block is present but parse.y does https://bugs.ruby-lang.org/issues/21168 * Author: Earlopain (Earlopain _) * Status: Open * ruby -v: ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [x86_64-linux] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- It's a bit more than that but explaining it in full would be a bit much. Instead, see this: ```rb foo( bar baz do end ) ``` ```sh $ ruby -c --parser=prism test.rb Syntax OK $ ruby -c --parser=parse.y test.rb ruby: test.rb:2: syntax error, unexpected 'do' for block, expecting ')' (SyntaxError) bar baz do ^~ ``` OTOH, this is consistently rejected: ```rb [ foo bar do end, ] # And also foo || bar baz do end ``` -- https://bugs.ruby-lang.org/

5 6

[ruby-core:116083] [Ruby master Feature#20163] Introduce #bit_count method on Integer
by garrison (Garrison Jensen) 18 Sep '25

18 Sep '25

Issue #20163 has been reported by garrison (Garrison Jensen). ---------------------------------------- Feature #20163: Introduce #bit_count method on Integer https://bugs.ruby-lang.org/issues/20163 * Author: garrison (Garrison Jensen) * Status: Open * Priority: Normal ---------------------------------------- This feature request is to implement a method called #bit_count on Integer that returns the number of ones in the binary representation of the absolute value of the integer. ``` n = 19 n.bit_count #=> 3 (-n).bit_count #=> 3 ``` This is often useful when you use an integer as a bitmask and want to count how many bits are set. This would be equivalent to ``` n.to_s(2).count("1") ``` However, this can be outperformed by ``` def bit_count(n) count = 0 while n > 0 n &= n - 1 # Flip the least significant 1 bit to 0 count += 1 end count end ``` I think this would be a useful addition because it would fit alongside the other bit-related methods defined on integer: `#bit_length,` `#allbits?`, `#anybits?`, `#nobits?`. Also, when working with bitmasks, a minor upgrade to performance often results in a significant improvement. Similar methods from other languages: https://docs.python.org/3/library/stdtypes.html#int.bit_count https://doc.rust-lang.org/std/primitive.i32.html#method.count_ones -- https://bugs.ruby-lang.org/

11 19

[ruby-core:122274] [Ruby Bug#21370] `it` can cause ISeq serialization failure
by byroot (Jean Boussier) 16 Sep '25

16 Sep '25

Issue #21370 has been reported by byroot (Jean Boussier). ---------------------------------------- Bug #21370: `it` can cause ISeq serialization failure https://bugs.ruby-lang.org/issues/21370 * Author: byroot (Jean Boussier) * Status: Open * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- Originally reported at: https://github.com/rails/rails/issues/55108 ```ruby iseq = RubyVM::InstructionSequence.compile(<<~'RUBY') [1].each do rescue => e puts it end RUBY iseq.to_binary # CRASH ``` ``` miniruby(sigsegv) (null):0 miniruby(RB_FL_ANY_RAW+0x20) [0x1010ac504] internal/fl_type.h:507 miniruby(rbimpl_rstring_getmem+0x20) [0x101090674] internal/core/rstring.h:393 miniruby(rb_str_cmp+0x4c) [0x10109920c] string.c:4541 miniruby(outer_variable_cmp+0x3c) [0x100e43b64] compile.c:13381 miniruby(cmp_bsd_qsort+0x3c) [0x1010fe810] util.c:239 miniruby(ruby_qsort+0x5c) [0x1010fe7a8] util.c:248 miniruby(ibf_dump_outer_variables+0x150) [0x100e43708] compile.c:13402 miniruby(ibf_dump_iseq_each+0x19c) [0x100e423cc] compile.c:13527 miniruby(ibf_dump_iseq_list_i+0x38) [0x100e420fc] compile.c:13862 miniruby(apply_functor+0x40) [0x10107bad8] st.c:1644 ``` It is crashing while trying to sort outer variables, and `it` is anonymous. -- https://bugs.ruby-lang.org/

2 6

[ruby-core:121865] [Ruby Bug#21313] `it` in rescue/ensure on prism
by ko1 (Koichi Sasada) 16 Sep '25

16 Sep '25

Issue #21313 has been reported by ko1 (Koichi Sasada). ---------------------------------------- Bug #21313: `it` in rescue/ensure on prism https://bugs.ruby-lang.org/issues/21313 * Author: ko1 (Koichi Sasada) * Status: Open * Assignee: prism * ruby -v: "ruby 3.4.1 (2024-12-25 revision 48d4efcb85) +PRISM [wasm32-wasi]" * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ```ruby 1.times do raise rescue p it #=> prism: false #=> parse.y: 0 end ``` `it` should return 0, shouldn't it? demo: parse.y: https://ruby.github.io/play-ruby/?code=p+RUBY_DESCRIPTION%0A%0A1.times+do%0… prism: https://ruby.github.io/play-ruby/?code=p+RUBY_DESCRIPTION%0A%0A1.times+do%0… Same on `ensure`. ```ruby 1.times do raise ensure p it #=> prism: false #=> parse.y: 0 end ``` ```ruby 1.times do begin raise ensure p it #=> prism: false #=> parse.y: 0 end end ``` -- https://bugs.ruby-lang.org/

4 3

[ruby-core:123113] [Ruby Feature#21555] Add support for predicate attribute reader names
by shan (Shannon Skipper) 16 Sep '25

16 Sep '25

Issue #21555 has been reported by shan (Shannon Skipper). ---------------------------------------- Feature #21555: Add support for predicate attribute reader names https://bugs.ruby-lang.org/issues/21555 * Author: shan (Shannon Skipper) * Status: Open ---------------------------------------- After manually aliasing predicate methods many times, I wanted to propose letting `attr_reader` take predicate method names that correspond to instance variables of the base name without a trailing question mark. https://github.com/ruby/ruby/pull/14391 If the base name method doesn't already exist, a predicate name defines a base name method attribute reader to alias then undefines the base name. For example, this creates an `enabled?` method that reads `@enabled`: ```ruby attr_reader :enabled? ``` This feature is only supported for `attr_reader` and `attr`, not `attr_writer` or `attr_accessor`, since setter methods cannot have question marks. Example: ```ruby class Example attr_reader :valid?, :meaning def initialize @valid = [true, false].sample @meaning = 42 end end Example.new.valid? #=> true ``` -- https://bugs.ruby-lang.org/

4 5

[ruby-core:122086] [Ruby Bug#21337] Using `not` on the RHS of a logical operator becomes valid syntax with Prism
by koic (Koichi ITO) 15 Sep '25

15 Sep '25

Issue #21337 has been reported by koic (Koichi ITO). ---------------------------------------- Bug #21337: Using `not` on the RHS of a logical operator becomes valid syntax with Prism https://bugs.ruby-lang.org/issues/21337 * Author: koic (Koichi ITO) * Status: Open * ruby -v: ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- The following syntax behavior differs between Ruby 3.3 (parse.y by default) and Ruby 3.4 (Prism by default). ```ruby if true && not true; end ``` ## Expected In Ruby 3.3 and earlier, the following code results in a syntax error. The default parser is `parse.y`. ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The key point is that `not` is used on the right-hand side of a logical operator. ## Actual When the default parser is switched to Prism, it is accepted as valid syntax with Ruby 3.4+ (Prism by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +PRISM [x86_64-darwin24] Syntax OK $ ruby -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) +PRISM [x86_64-darwin24] Syntax OK ``` Specifying parse.y causes a syntax error, as before 3.3 (parse.y by default): ```console $ ruby -vce 'if true && not true; end' ruby 3.3.8 (2025-04-09 revision b200bad6cd) [x86_64-darwin24] -e:1: syntax error, unexpected `true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) $ ruby --parser=parse.y -vce 'if true && not true; end' ruby 3.5.0dev (2025-05-13T02:05:19Z master 9b8c846bdf) [x86_64-darwin24] -e:1: syntax error, unexpected 'true', expecting '(' if true && not true; end ruby: compile error (SyntaxError) ``` The behavior seen in the parse.y producing a syntax error might be probably the expected one. Any case, it is likely that users would not expect such a discrepancy between parsers. This issue was noticed in the context of the following RuboCop issue: https://github.com/rubocop/rubocop/issues/14177 -- https://bugs.ruby-lang.org/

7 6

[ruby-core:121390] [Ruby Bug#21188] PRISM does not end reading from tty with ^D twice
by nobu (Nobuyoshi Nakada) 15 Sep '25

15 Sep '25

Issue #21188 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21188: PRISM does not end reading from tty with ^D twice https://bugs.ruby-lang.org/issues/21188 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Assignee: prism * Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- When reading from tty, `^D` ends the text without the newline. ```console $ cat a ``` Typing `^D` here, only "a" is sent without a newline, and `cat` echos back it. Then by typing `^D` again, an empty read that means EOF causes `cat` to exit. `ruby --parser=parse.y` behaves in this manner: ```console $ ruby --parser=parse.y p __FILE__"-" ``` Typing `^D` twice just after `__FILE__`, and `p` prints `"-"`. However prism requires `^D` thrice. -- https://bugs.ruby-lang.org/

2 1

[ruby-core:122953] [Ruby Bug#21540] prism allows `foo && return bar` when parse.y doesn't
by Earlopain (Earlopain _) 15 Sep '25

15 Sep '25

Issue #21540 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21540: prism allows `foo && return bar` when parse.y doesn't https://bugs.ruby-lang.org/issues/21540 * Author: Earlopain (Earlopain _) * Status: Open * ruby -v: ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Code such as `foo && return bar` has been disallowed in ruby since at least Ruby 2.0. Prism allows it though: ``` $ ruby -cve "a && return foo" ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) +PRISM [x86_64-linux] Syntax OK $ ruby --parser=parse.y -cve "a && return foo" ruby 3.5.0dev (2025-08-08T02:57:23Z master 3ad26d0501) [x86_64-linux] -e:1: syntax error, unexpected local variable or method, expecting end-of-input a && return foo ruby: compile error (SyntaxError) ``` The code seems to behave like I'd expect it to and I wouldn't mind it being accepted but it is inconsistent. -- https://bugs.ruby-lang.org/

6 11

[ruby-core:122972] [Ruby Bug#21546] `prefix` in ruby.pc is wrong when `--enable-load-relative`
by nobu (Nobuyoshi Nakada) 14 Sep '25

14 Sep '25

Issue #21546 has been reported by nobu (Nobuyoshi Nakada). ---------------------------------------- Bug #21546: `prefix` in ruby.pc is wrong when `--enable-load-relative` https://bugs.ruby-lang.org/issues/21546 * Author: nobu (Nobuyoshi Nakada) * Status: Open * Backport: 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED ---------------------------------------- It is relocatable and should reflect the installed location. ```console $ export PKG_CONFIG_PATH=/opt/local/lib/pkgconfig${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH} $ pkg-config --variable=prefix ruby-3.5 /. ``` Currently `pkg-config --define-prefix` works because it overrides the `prefix` value. ```console $ pkg-config --variable=prefix --define-prefix ruby-3.5 /opt/local ``` -- https://bugs.ruby-lang.org/

3 2