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

[ruby-core:120819] [Ruby master Bug#21097] `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism
by tompng (tomoya ishida) 16 Mar '26

16 Mar '26

Issue #21097 has been reported by tompng (tomoya ishida). ---------------------------------------- Bug #21097: `x = a rescue b in c` and `def f = a rescue b in c` parsed differently between parse.y and prism https://bugs.ruby-lang.org/issues/21097 * Author: tompng (tomoya ishida) * Status: Open * ruby -v: ruby 3.5.0dev (2025-01-27T08:19:32Z master c3c7300b89) +YJIT +MN +PRISM [arm64-darwin22] * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- ~~~ruby x = a rescue b in c (x = (a rescue b)) in c # parse.y, prism(ruby 3.4) x = (a rescue (b in c)) # prism(ruby 3.5) ~~~ ~~~ruby def f = a rescue b in c #=> true(parse.y), :f(prism) (def f = (a rescue b)) in c # parse.y def f = (a rescue (b in c)) # prism ~~~ There is no difference between prism and parse.y parsing these codes ~~~ruby a rescue b in c # a rescue (b in c) x = a rescue b # x = (a rescue b) x = b in c # (x = b) in c def f = a rescue b # def f = (a rescue b) def f = b in c # (def f = a) in b ~~~ -- https://bugs.ruby-lang.org/

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[ruby-core:124934] [Ruby Bug#21945] Ripper lexes newline between identifier and `and?` as ignored newline
by Earlopain (Earlopain _) 16 Mar '26

16 Mar '26

Issue #21945 has been reported by Earlopain (Earlopain _). ---------------------------------------- Bug #21945: Ripper lexes newline between identifier and `and?` as ignored newline https://bugs.ruby-lang.org/issues/21945 * Author: Earlopain (Earlopain _) * Status: Open * ruby -v: ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [x86_64-linux] * Backport: 3.2: DONTNEED, 3.3: DONTNEED, 3.4: DONTNEED, 4.0: UNKNOWN ---------------------------------------- ```rb Ripper.lex("foo\nand?") => [[[1, 0], :on_ident, "foo", CMDARG], [[1, 3], :on_ignored_nl, "\n", CMDARG], [[2, 0], :on_ident, "and?", ARG]] ``` Presumably this is because until the `?` is encountered, it is considered syntax as introduced in https://bugs.ruby-lang.org/issues/20925. The same is true for `and!` and `or`. If any other character is encountered, it lexes correctly like in `foo\nandbar`. -- https://bugs.ruby-lang.org/

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[ruby-core:124950] [Ruby Bug#21947] `Timeout.timeout` doesn't use `Timeout::ExitException` when Fiber scheduler is in use.
by ioquatix (Samuel Williams) 16 Mar '26

16 Mar '26

Issue #21947 has been reported by ioquatix (Samuel Williams). ---------------------------------------- Bug #21947: `Timeout.timeout` doesn't use `Timeout::ExitException` when Fiber scheduler is in use. https://bugs.ruby-lang.org/issues/21947 * Author: ioquatix (Samuel Williams) * Status: Open * Assignee: ioquatix (Samuel Williams) * Backport: 3.3: REQUIRED, 3.4: REQUIRED, 4.0: REQUIRED ---------------------------------------- The following example executes successfully after 7 seconds instead of timing out after 2. ```ruby require 'async' require 'net/http' start = Time.now Sync do Timeout.timeout 2 do Net::HTTP.get(URI 'https://httpbin.org/delay/5') puts "...request finished, no timeout though; in #{Time.now - start}s" end end puts "Duration: #{Time.now - start}s" # => ...request finished, no timeout though; in 7.7007s # Duration: 7.700962s ``` There are two issues: - `Net::HTTP` rescues `Timeout::Error` and retries. This causes 2s (timeout -> retry) + 5s execution time. - `Timeout.timeout` uses `Timeout::ExitException` when no exception is specified, but the Fiber scheduler code path was not updated. See <https://github.com/socketry/async/issues/448> for more discussion. -- https://bugs.ruby-lang.org/

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[ruby-core:124920] [Ruby Bug#21941] Local variable becomes nil when YJIT enabled mid-method with fork/signal/ensure
by nicholasdower (Nick Dower) 16 Mar '26

16 Mar '26

Issue #21941 has been reported by nicholasdower (Nick Dower). ---------------------------------------- Bug #21941: Local variable becomes nil when YJIT enabled mid-method with fork/signal/ensure https://bugs.ruby-lang.org/issues/21941 * Author: nicholasdower (Nick Dower) * Status: Open * ruby -v: ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [arm64-darwin25] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- The following code results in the `read` local variable becoming nil, even though it is never reassigned: ``` def run fork_safe = ->(t) { t } RubyVM::YJIT.enable read, wakeup = IO.pipe Signal.trap("SIGCHLD") { wakeup.write("!") } begin while true begin fork { exit } next if read.wait_readable rescue Interrupt end end ensure end end run ``` Error: ``` repro.rb:13:in 'Object#run': undefined method 'wait_readable' for nil (NoMethodError) next if read.wait_readable ^^^^^^^^^^^^^^ from repro.rb:21:in '<main>' ``` See also: https://github.com/puma/puma/issues/3620 https://github.com/Shopify/ruby/issues/625 -- https://bugs.ruby-lang.org/

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[ruby-core:124848] [Ruby Bug#21917] Unable to build 4.0.1 on AIX 7.2
by mhashizume (Michael Hashizume) 16 Mar '26

16 Mar '26

Issue #21917 has been reported by mhashizume (Michael Hashizume). ---------------------------------------- Bug #21917: Unable to build 4.0.1 on AIX 7.2 https://bugs.ruby-lang.org/issues/21917 * Author: mhashizume (Michael Hashizume) * Status: Open * ruby -v: 4.0.1 * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- I'm attempting to build Ruby 4.0.1 on AIX 7.2. We have had successful builds of previous versions of Ruby on this platform, but are starting to see an issue when using miniruby to build Ruby: ``` shell ./miniruby -I./lib -I. -I.ext/common ./tool/runruby.rb --extout=.ext -- --disable-gems -r./powerpc64-aix7.2.0.0-fake ./tool/rbinstall.rb --make="gmake" --dest-dir="" --extout=".ext" --ext-build-dir="./ext" --mflags="-j3 --jobserver-auth=fifo:/tmp//GMfifo9306586" --make-flags=" -j3 --jobserver-auth=fifo:/tmp//GMfifo9306586" --data-mode=0644 --prog-mode=0755 --installed-list .installed.list --mantype="man" --install=all --exclude=doc /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/common/monitor.rb:10:in 'Kernel#require': false() function is unimplemented on this machine (NotImplementedError) from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/common/monitor.rb:10:in '<top (required)>' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in '<top (required)>' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in 'Kernel#eval' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in '<top (required)>' from ./tool/rbinstall.rb:25:in 'Kernel#require' from ./tool/rbinstall.rb:25:in '<main>' ``` I'm not sure where the NotImplementedError is coming from, and when looking at the `truss` output from miniruby, I see a ENOTTY when miniruby attempts to load monitor.so: ```shell accessx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/powerpc64-aix7.2.0.0/monitor.so", 0, 0) = 0 statx("/", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp/tmp.INfzUXAeGi", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/powerpc64-aix7.2.0.0", 0x0FFFFFFFFFFFA680, 176, 011) = 0 statx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/powerpc64-aix7.2.0.0/monitor.so", 0x0FFFFFFFFFFFA680, 176, 011) = 0 __ksetjmp(0x0000000110019F88, 0x09000000026845A8, 2, 0x000000011001A1D8, 0x0FFFFFFFFFFFB790, 0x0000000022242202, 0x000000011011A658, 0x09000 00000260348) = 0 statx("/var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/powerpc64-aix7.2.0.0/monitor.so", 0x0FFFFFFFFFFFB800, 176, 0) = 0 kioctl(2, 22528, 0x0000000000000000, 0x0000000000000000) Err#25 ENOTTY /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/common/monitor.rb:10:in 'Kernel#require': false() function is unimplemented on this machine (NotImpl ementedError) from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/.ext/common/monitor.rb:10:in '<top (required)>' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in '<top (required)>' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in 'Kernel#eval' from /var/tmp/tmp.INfzUXAeGi/ruby-4.0.1/lib/rubygems.rb:1452:in '<top (required)>' from ./tool/rbinstall.rb:25:in 'Kernel#require' from ./tool/rbinstall.rb:25:in '<main>' ``` monitor.so is present in the path that miniruby is looking for it. Any pointers on where to start debugging this further or what changes in more recent versions of Ruby could have caused this would be greatly appreciated. Thank you! -- https://bugs.ruby-lang.org/

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[ruby-core:124918] [Ruby Bug#21940] Ruby::Box: `$_` returns stale value due to gvar_tbl caching
by dak2 (Daichi Kamiyama) 16 Mar '26

16 Mar '26

Issue #21940 has been reported by dak2 (Daichi Kamiyama). ---------------------------------------- Bug #21940: Ruby::Box: `$_` returns stale value due to gvar_tbl caching https://bugs.ruby-lang.org/issues/21940 * Author: dak2 (Daichi Kamiyama) * Status: Open * ruby -v: 4.0.1 * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ## Environment - Ruby Version v4.0.1 - OS: macOS 15.6.1 (arm64) - `RUBY_BOX=1` enabled ## Reproduction ```shell echo -e "a\nb" | RUBY_BOX=1 ruby -e 'gets; $_; gets; p $_' ``` ## Expected ``` "b\n" ``` The second gets reads `"b"` and sets it to `$_`. `p $_` should return the latest value. ## Actual ``` "a\n" ``` `$_` returns the stale value from the first gets. ## Root Cause `$_` is a special variable stored in `svar`. Its getter (`rb_lastline_get`) reads the current value from svar each time it is called. However, when Box is enabled, I believe `rb_gvar_get()` caches the value in the Box's `gvar_tbl` on first access. On subsequent reads, it returns the cached value directly without calling the getter. Since gets updates `$_` via `rb_lastline_set()` which bypasses `rb_gvar_set()`, the cache becomes stale. -- https://bugs.ruby-lang.org/

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[ruby-core:124906] [Ruby Bug#21934] Prism and parse.y inconsistency in command call used with pattern match
by tompng (tomoya ishida) 16 Mar '26

16 Mar '26

Issue #21934 has been reported by tompng (tomoya ishida). ---------------------------------------- Bug #21934: Prism and parse.y inconsistency in command call used with pattern match https://bugs.ruby-lang.org/issues/21934 * Author: tompng (tomoya ishida) * Status: Open * ruby -v: ruby 4.1.0dev (2026-03-03T16:19:28Z master e30b5a06dc) +PRISM [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- These are syntax error in both parse.y and in Prism ~~~ruby a x in pattern a x: in pattern a &x in pattern a *x => pattern a x: => pattern a &x => pattern ~~~ These are all syntax error in parse.y, all syntax valid in Prism ~~~ruby a.b x in pattern a.b x: in pattern a.b &x in pattern a.b *x => pattern a.b x: => pattern a.b &x => pattern ~~~ I think this is related to https://github.com/ruby/prism/issues/3558, `A.print message:\nin 'BAR'` inside case-in was parsed as `(A.print message:) in 'BAR'`. -- https://bugs.ruby-lang.org/

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[ruby-core:124443] [Ruby Bug#21828] An incorrect warning message related to `benchmark` is shown when using `benchmark-ips`
by y-yagi (Yuji Yaginuma) 16 Mar '26

16 Mar '26

Issue #21828 has been reported by y-yagi (Yuji Yaginuma). ---------------------------------------- Bug #21828: An incorrect warning message related to `benchmark` is shown when using `benchmark-ips` https://bugs.ruby-lang.org/issues/21828 * Author: y-yagi (Yuji Yaginuma) * Status: Open * ruby -v: ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [x86_64-linux] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN ---------------------------------------- ## Descrition When using `benchmark-ips` gem with Ruby 4.0.0, the warning related to `benchmark` gem is shown. ## Step to reproduce ```ruby # Gemfile # frozen_string_literal: true source "https://rubygems.org" gem "benchmark-ips" ``` ```ruby # script.rb require "benchmark/ips" ``` ```text $ bundle exec ruby -v script.rb ruby 4.0.0 (2025-12-25 revision 553f1675f3) +PRISM [x86_64-linux] script.rb:1: warning: benchmark/ips is found in benchmark, which is not part of the default gems since Ruby 4.0.0. You can add benchmark to your Gemfile or gemspec to fix this error. ``` ## Expected behavior The warning for `benchmark` isn't shown when using `benchmark-ips`. -- https://bugs.ruby-lang.org/

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[ruby-core:125003] [Ruby Feature#21953] Allow accessing unshareable objects within a Ractor-local Ruby Box
by tikkss (Tsutomu Katsube) 15 Mar '26

15 Mar '26

Issue #21953 has been reported by tikkss (Tsutomu Katsube). ---------------------------------------- Feature #21953: Allow accessing unshareable objects within a Ractor-local Ruby Box https://bugs.ruby-lang.org/issues/21953 * Author: tikkss (Tsutomu Katsube) * Status: Open ---------------------------------------- ### Status Currently, non-main ractors prohibit access to the following objects to prevent data races: * Global variables * Class variables * Unshareable class instance variables * Unshareable constants ### Proposal I would like to propose that allow reading/writing unshareable objects inside a Ruby Box created in a non-main ractor: ```ruby # lib/x.rb class X # can write unshareable objects XXX = "1" @@cvar = "1" @ivar = "1" class << self def cvar; @@cvar; end def ivar; @ivar; end end end # can read unshareable objects $LOAD_PATH # => returns $LOAD_PATH includes lib directory X.cvar # => "1" X.ivar # => "1" X::XXX # => "1" # main.rb Ractor.new do local_box = Ruby::Box.new local_box.eval <<~RUBY base_dir = File.expand_path(File.dirname(__FILE__)) lib_dir = File.join(base_dir, "lib") # can write unshareable objects $LOAD_PATH.unshift(lib_dir) RUBY local_box.require("x") x = local_box::X.new end.join ``` Ruby Box can isolate global/class variables, class/module definitions from other boxes. A Ruby Box created inside a non-main ractor cannot be accessed from other ractor. If that is the case, wouldn’t it be fine to access unshareable objects inside that box? So I would like to propose that allow reading/writing unshareable objects inside a Ruby Box created in a non-main ractor. ### Background We are working on implementing a Ractor based parallel test runner for the test-unit gem. Ractor is a great for parallel processing. However, many existing libraries still rely on class variables or class instance variables for configuration. Ideally, we should reduce the use of class variables or class instance variables. Currently, we tried fixing several non-shareable objects, but we could not resolve all of them yet. We will continue working on this issue, but we are also exploring other approaches. This is the idea begind this proposal. I think the work needed to make objects shareable when running exisiting libraries with Ractor can be reduced. ### FAQ Q: Can we create a Ruby Box inside a non-main ractor? A: Yes: ```ruby Ractor.new {Ruby::Box.new}.join ``` Q: Is a Ruby Box created in a non-main ractor truly inaccessible from other ractor? A: No. I'm not sure if it's intentional, but a Ruby Box is a shareable object. Also, it can be accessed from the main Ractor by using `Ractor#value`: ```ruby Ractor.shareable?(Ruby::Box.new) # => true ``` ```ruby Ractor.new {Ruby::Box.new}.value # => #<Ruby::Box:3,user,optional> ``` To implement this proposal, Ruby Box may need to be an unshareable object, and passing it with `Ractor#value` may need to be disallowed. -- https://bugs.ruby-lang.org/

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[ruby-core:116589] [Ruby master Misc#20238] Use prism for mk_builtin_loader.rb
by kddnewton (Kevin Newton) 13 Mar '26

13 Mar '26

Issue #20238 has been reported by kddnewton (Kevin Newton). ---------------------------------------- Misc #20238: Use prism for mk_builtin_loader.rb https://bugs.ruby-lang.org/issues/20238 * Author: kddnewton (Kevin Newton) * Status: Open * Priority: Normal ---------------------------------------- I would like to propose that we use prism for mk_builtin_loader.rb. Right now the Ruby syntax that you can use in builtin classes is restricted to the base Ruby version (2.7). This means you can't use a lot of the nicer syntax that Ruby has shipped in the last couple of years. If we switch to using prism to parse the builtin files instead of using ripper, then we can always use the latest version of Ruby syntax. A pull request for this is here: https://github.com/kddnewton/ruby/pull/65. The approach for the PR is taken from how RJIT bindgen works. -- https://bugs.ruby-lang.org/

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