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

[ruby-core:122261] [Ruby Bug#21368] Moving objects with finalizer between Ractors crashes
by peterzhu2118 (Peter Zhu) 11 Jun '25

11 Jun '25

Issue #21368 has been reported by peterzhu2118 (Peter Zhu). ---------------------------------------- Bug #21368: Moving objects with finalizer between Ractors crashes https://bugs.ruby-lang.org/issues/21368 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- When an object is moved to a different Ractor, the finalizers are not copied to the new object, so it will have the `FL_FINALIZE` flag set but no entry in the finalizer table. The following script crashes: ```ruby r = Ractor.new do loop { Ractor.receive } end 1_000.times do o = Object.new ObjectSpace.define_finalizer(o, proc { |id| }) r.send(o, move: true) end ``` -- https://bugs.ruby-lang.org/

3 5

[ruby-core:118577] [Ruby master Bug#20631] Build failure with Xcode 16 beta and macOS 15 (Sequoia) Beta
by hsbt (Hiroshi SHIBATA) 11 Jun '25

11 Jun '25

Issue #20631 has been reported by hsbt (Hiroshi SHIBATA). ---------------------------------------- Bug #20631: Build failure with Xcode 16 beta and macOS 15 (Sequoia) Beta https://bugs.ruby-lang.org/issues/20631 * Author: hsbt (Hiroshi SHIBATA) * Status: Open * Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- I found some issues with Xcode 16 beta and macOS 15 (Sequoia) Beta. `TestRubyOptions` and `TestVMDump` are failed with them. full log: https://gist.github.com/hsbt/378fe2ba47e734f2562ba9a154e1795b I'm not sure why macOS require `sudo` command for that. ---- And I and @katei also found the regression of https://bugs.ruby-lang.org/issues/18912#note-15. ``` >> pid = fork { p File.realpath "/" } >> Process.waitpid(pid) objc[82573]: +[NSPlaceholderMutableString initialize] may have been in progress in another thread when fork() was called. objc[82573]: +[NSPlaceholderMutableString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug. => 82573 ``` -- https://bugs.ruby-lang.org/

2 8

[ruby-core:122352] [Ruby Bug#21388] make install and bundled gems
by MSP-Greg (Greg L) 10 Jun '25

10 Jun '25

Issue #21388 has been reported by MSP-Greg (Greg L). ---------------------------------------- Bug #21388: make install and bundled gems https://bugs.ruby-lang.org/issues/21388 * Author: MSP-Greg (Greg L) * Status: Open * ruby -v: ruby 3.5.0dev (2025-05-31T09:43:52Z master 32c708efbd) +PRISM [x64-mingw-ucrt] * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- Two issues: 1. Currently, `make install` from the `MinGW (UCRT)` workflow shows two gems not being installed (`syslog` cannot be installed on Windows): ``` skipped bundled gems: csv-3.3.5.gem not found in bundled_gems power_assert-2.0.6dev.gem not found in bundled_gems syslog-0.3.0.gem not found in bundled_gems ``` A simple patch file will fix this: ```patch diff --git a/gems/bundled_gems b/gems/bundled_gems index 8891f1c462..ca66b48ed6 100644 --- a/gems/bundled_gems +++ b/gems/bundled_gems @@ -7,7 +7,7 @@ # if `revision` is not given, "v"+`version` or `version` will be used. minitest 5.25.5 https://github.com/minitest/minitest -power_assert 2.0.5 https://github.com/ruby/power_assert a7dab941153b233d3412e249d25da52a6c5691de +power_assert 2.0.6dev https://github.com/ruby/power_assert a7dab941153b233d3412e249d25da52a6c5691de rake 13.3.0 https://github.com/ruby/rake test-unit 3.6.8 https://github.com/test-unit/test-unit rexml 3.4.1 https://github.com/ruby/rexml @@ -33,7 +33,7 @@ rinda 0.2.0 https://github.com/ruby/rinda drb 2.2.3 https://github.com/ruby/drb nkf 0.2.0 https://github.com/ruby/nkf syslog 0.3.0 https://github.com/ruby/syslog -csv 3.3.4 https://github.com/ruby/csv 69d9886238a504bfac60fa516cd08ad2a855a2a8 +csv 3.3.5 https://github.com/ruby/csv 69d9886238a504bfac60fa516cd08ad2a855a2a8 repl_type_completor 0.1.11 https://github.com/ruby/repl_type_completor 25108aa8d69ddaba0b5da3feff1c0035371524b2 ostruct 0.6.1 https://github.com/ruby/ostruct 50d51248bec5560a102a1024aff4174b31dca8cc pstore 0.2.0 https://github.com/ruby/pstore ``` 2. Sometime ago, one could cache the *.gem files, and they would not be downloaded. Now, regardless of the cache, they are always downloaded. -- https://bugs.ruby-lang.org/

3 3

[ruby-core:118412] [Ruby master Misc#20600] @ruby-lang.org has been migrated to Cloudflare
by shugo (Shugo Maeda) 10 Jun '25

10 Jun '25

Issue #20600 has been reported by shugo (Shugo Maeda). ---------------------------------------- Misc #20600: @ruby-lang.org has been migrated to Cloudflare https://bugs.ruby-lang.org/issues/20600 * Author: shugo (Shugo Maeda) * Status: Open ---------------------------------------- @ruby-lang.org has been migrated to Cloudflare, because ruby-lang.org was migrated from Google Domains to Squarespace, and Squarespace's e-mail forwarding doesn't work with custom MX records including subdomains:( I and Shibata-san are adding e-mail routing rules on Cloudflare, so if you have an e-mail address on ruby-lang.org, please verify the e-mail routing address when receiving an email from Cloudflare. -- https://bugs.ruby-lang.org/

6 13

[ruby-core:119683] [Ruby master Feature#20861] Add an environment variable for tuning the default thread quantum
by tenderlovemaking (Aaron Patterson) 08 Jun '25

08 Jun '25

Issue #20861 has been reported by tenderlovemaking (Aaron Patterson). ---------------------------------------- Feature #20861: Add an environment variable for tuning the default thread quantum https://bugs.ruby-lang.org/issues/20861 * Author: tenderlovemaking (Aaron Patterson) * Status: Open ---------------------------------------- The default thread quantum is currently [hard coded at 100ms](https://github.com/ruby/ruby/blob/c7708d22c33040a74ea7ac683bf7407d37…. This can impact multithreaded systems that are trying to process Ruby level CPU bound work at the same time as IO work. I would like to add an environment variable `RUBY_THREAD_DEFAULT_QUANTUM_MS` that allows users to specify the default thread quantum (in milliseconds) via an environment variable. It defaults to our current default of 100ms. I've submitted the patch [here](https://github.com/ruby/ruby/pull/11981). Here is a Ruby program to demonstrate the problem: ```ruby def measure x = Process.clock_gettime(Process::CLOCK_MONOTONIC) yield Process.clock_gettime(Process::CLOCK_MONOTONIC) - x end def fib(n) if n < 2 n else fib(n-2) + fib(n-1) end end # find fib that takes ~500ms fib_i = 50.times.find { |i| measure { fib(i) } >= 0.05 } sleep_i = measure { fib(fib_i) } threads = [ Thread.new { 100.times { sleep(sleep_i) # sometimes stalled waiting for fib's quantum to finish } puts "done 1" }, Thread.new { 100.times { fib(fib_i) }; puts "done 2" }, ] # We expect the total time to be about 100 * sleep_i (~5 seconds) because # theoretically the sleep thread could be done nearly completely in parallel to # the fib thread. # # But because the `sleep` thread is iterating over the sleep call, it must wait # for the `fib` thread to complete its quantum, before it can start the next iteration. # # This means each sleep iteration could take up to `sleep_i + 100ms` # # We're calling that stalled time "waste" total = measure { threads.each(&:join) } waste = total - (sleep_i * 100) p TOTAL: total, WASTE: waste ``` The program has two threads. One thread is using CPU time by computing `fib` in a loop. The other thread is simulating IO time by calling `sleep` in a loop. When the `sleep` call completes, it can stall, waiting for the quantum in the fib thread to expire. That means that each iteration on sleep can actually take `sleep time + thread quantum`, or in this case ~600ms when we expected it to only take ~500ms. Ideally, the above program would take `500ms * 100` since all `sleep` calls should be able to execute in parallel with the `fib` calls. Of course this isn't true because the sleep thread must acquire the GVL before it can continue the next iteration, so there will always be _some_ overhead. This feature is for allowing people to tune that overhead. If we run this program with the default quantum the output looks like this: ``` $ ./miniruby -v fibtest.rb ruby 3.4.0dev (2024-11-01T14:49:50Z quantum-computing c7708d22c3) +PRISM [arm64-darwin24] done 2 done 1 {TOTAL: 12.672821999993175, WASTE: 4.960721996147186} ``` The output shows that our program spent about 5 seconds stalled, waiting to acquire the GVL. With this patch we can lower the default quantum, and the output is like this: ``` $ RUBY_THREAD_DEFAULT_QUANTUM_MS=10 ./miniruby -v fibtest.rb ruby 3.4.0dev (2024-11-01T22:06:35Z quantum-computing 087500643d) +PRISM [arm64-darwin24] done 2 done 1 {TOTAL: 8.898526000091806, WASTE: 1.4168260043952614} ``` Specifying the ENV to change the quantum to 10ms lowered our waste in the program to ~1.4 seconds. It's common for web applications to do mixed CPU and IO bound tasks in threads (see the Puma webserver), so it would be great if there was a way to customize the thread quantum depending on your application's workload. -- https://bugs.ruby-lang.org/

11 23

[ruby-core:115981] [Ruby master Bug#20105] Introduce `IO::Stream` or something similar.
by ioquatix (Samuel Williams) 07 Jun '25

07 Jun '25

Issue #20105 has been reported by ioquatix (Samuel Williams). ---------------------------------------- Bug #20105: Introduce `IO::Stream` or something similar. https://bugs.ruby-lang.org/issues/20105 * Author: ioquatix (Samuel Williams) * Status: Open * Priority: Normal * Assignee: ioquatix (Samuel Williams) * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- Ruby's IO class has a general model for streaming IO, including some hidden classes like `IO::generic_readable` and `IO::generic_writable`. As Ruby's core IO classes evolve, gems like `openssl` (see `OpenSSL::Buffering`) need to be updated to support changes to the interface. As it stands, there are changes in `IO` which are not copied to `OpenSSL::Buffering`. I'd like to propose we introduce some shared interface for streams that is used by `IO`, `Socket`, and `OpenSSL` to start with. The general interface would be similar to `IO` and allow code like `OpenSSL` to avoid re-implementing the `IO` interface. -- https://bugs.ruby-lang.org/

2 2

[ruby-core:121551] [Ruby Feature#21219] `Object#inspect` accept a list of instance variables to display
by byroot (Jean Boussier) 07 Jun '25

07 Jun '25

Issue #21219 has been reported by byroot (Jean Boussier). ---------------------------------------- Feature #21219: `Object#inspect` accept a list of instance variables to display https://bugs.ruby-lang.org/issues/21219 * Author: byroot (Jean Boussier) * Status: Open ---------------------------------------- ## Context The default `Object#inspect` implementation is quite useful to have a generic representation of objects in error message and similar places. However sometimes objects are referencing other objects with a very large `inspect` representation, making error message hard to understand. In some other cases, some instance variables are holding secrets such as password or private keys, and the default inspect behavior can cause these secrets to be leaked in logs among other places. You can of course define your own `inspect` implementation for any object, but it's not as simple as it may seems because you need to handle circular references, otherwise you can end up with a `SystemStackError`. Also, it's more minor, but since Ruby 2.7, you can no longer access an object's address, so you can't implement an `inspect` method that is consistent with `Object#inspect` From my experience, user defined implementations of `#inspect` are very rare, and I think the above is in part responsible. ## Feature I think it would be useful if the default `Object#inspect` implementation accepted a list of instance variables to display, so that you could very easily hide internal state, either because it's too verbose, or because it is secret: ```ruby require 'logger' logger = Logger.new(STDOUT) class DatabaseConfig def initialize(host, user, password) @host = host @user = user @password = password end def inspect = super(instance_variables: [:@host, :@user]) end env = {db_config: DatabaseConfig.new("localhost", "root", "hunter2")} logger.info("something happened, env: #{env}") ``` ``` INFO -- : something happened, env: {db_config: #<DatabaseConfig:0x00000001002b3a08 @host="localhost", @user="root">} ``` -- https://bugs.ruby-lang.org/

6 9

[ruby-core:121182] [Ruby master Bug#21158] Ractor using 'receive_if' sits in busy wait when there are skipped messages in the incoming queue
by NeilW (Neil Wilson) 06 Jun '25

06 Jun '25

Issue #21158 has been reported by NeilW (Neil Wilson). ---------------------------------------- Bug #21158: Ractor using 'receive_if' sits in busy wait when there are skipped messages in the incoming queue https://bugs.ruby-lang.org/issues/21158 * Author: NeilW (Neil Wilson) * 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 ---------------------------------------- When using the conditional receive example from the Ractor documentation (either as a script, or within irb) <pre> r = Ractor.new do val = Ractor.receive_if{|msg| msg.is_a?(Array)} puts "Received successfully: #{val}" end r.send(1) r.send('test') </pre> ruby will sit in busy wait, pegging the processor at 100%, until it gets a message that matches the condition. Within irb it will often stop the REPL responding. The same problem occurs on ruby 3.02, 3.3.7 and 3.4.1 -- https://bugs.ruby-lang.org/

3 2

[ruby-core:122265] [Ruby Misc#21369] Propose Max Bernstein (@tekknolagi) as a core committer
by k0kubun (Takashi Kokubun) 06 Jun '25

06 Jun '25

Issue #21369 has been reported by k0kubun (Takashi Kokubun). ---------------------------------------- Misc #21369: Propose Max Bernstein (@tekknolagi) as a core committer https://bugs.ruby-lang.org/issues/21369 * Author: k0kubun (Takashi Kokubun) * Status: Open ---------------------------------------- ## Proposal I'd like to propose Max Bernstein (@tekknolagi) as a committer. He has a strong background in compilers, having previously worked on CPython/Cinder at Meta, and has demonstrated leadership in designing and optimizing ZJIT. Given that he is leading the development of the ZJIT IR and has been making a lot of contributions, I believe he should be empowered to merge such changes himself. I'll include his message below for reference: ## Max Bernstein's Message I have been working on Ruby since December 2024. My main contributions so far have been to ZJIT: * The high-level IR (HIR) data structures * The IR * The type lattice https://github.com/Shopify/zjit/pull/19 * Transforming YARV bytecode into HIR * Optimization on HIR, such as * Type inference https://github.com/Shopify/zjit/pull/23 * Constant folding https://github.com/Shopify/zjit/pull/74 * Direct calls https://github.com/Shopify/zjit/pull/84 * Strength reduction * Dead code elimination (DCE) https://github.com/Shopify/zjit/pull/89 After we moved the ZJIT repo into ruby/ruby, I have continued contributing (see [all PRs](https://github.com/ruby/ruby/pulls?q=author%3Atekknolagi)) I would like to continue contributing to ZJIT and eventually to other parts of Ruby too. Being a maintainer would make it easier to work on ZJIT, especially as we continue the project bringup phase. -- https://bugs.ruby-lang.org/

7 7

[ruby-core:121443] [Ruby Bug#21198] Fiber::Scheduler#blocking_operation_wait crash due to stack-use-after-return
by peterzhu2118 (Peter Zhu) 06 Jun '25

06 Jun '25

Issue #21198 has been reported by peterzhu2118 (Peter Zhu). ---------------------------------------- Bug #21198: Fiber::Scheduler#blocking_operation_wait crash due to stack-use-after-return https://bugs.ruby-lang.org/issues/21198 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Backport: 3.1: DONTNEED, 3.2: DONTNEED, 3.3: DONTNEED, 3.4: REQUIRED ---------------------------------------- The Fiber::Scheduler#blocking_operation_wait method is passed a proc through the `rb_fiber_scheduler_blocking_operation_wait` function. This function stack allocates the arguments used for the proc ([source](https://github.com/ruby/ruby/blob/2183899fd184ab1cfee80d57c0dd6f4dc…) If this proc is captured anywhere, then calling it again will illegally read from and write to stack space. The following script demonstrates this issue using the [test/fiber/scheduler.rb](https://github.com/ruby/ruby/blob/master/test/fibe… scheduler: ```ruby require_relative "test/fiber/scheduler" class MyScheduler < Scheduler def blocking_operation_wait(work) super $work = work end end scheduler = MyScheduler.new Fiber.set_scheduler(scheduler) require "tempfile" Fiber.schedule do file = Tempfile.new file.write("hello world!") $work.call end scheduler.run ``` Crashes with: ``` test.rb:19: [BUG] Bus Error at 0xce0f57696add0045 ruby 3.4.2 (2025-02-15 revision d2930f8e7a) +PRISM [arm64-darwin24] -- Crash Report log information -------------------------------------------- See Crash Report log file in one of the following locations: * ~/Library/Logs/DiagnosticReports * /Library/Logs/DiagnosticReports for more details. Don't forget to include the above Crash Report log file in bug reports. -- Control frame information ----------------------------------------------- c:0003 p:---- s:0010 e:000009 IFUNC c:0002 p:0017 s:0007 e:000006 BLOCK test.rb:19 [FINISH] c:0001 p:---- s:0003 e:000002 DUMMY [FINISH] -- Ruby level backtrace information ---------------------------------------- test.rb:19:in 'block in <main>' -- Threading information --------------------------------------------------- Total ractor count: 1 Ruby thread count for this ractor: 1 Note that the Fiber scheduler is enabled -- Machine register context ------------------------------------------------ x0: 0x000000010063a5f0 x1: 0x000000014b80ce00 x2: 0x0000000000000000 x3: 0x000000014b60f060 x4: 0x0000000000000000 x5: 0x0000000000000000 x6: 0x0000000000000004 x7: 0x0000000000000000 x18: 0x0000000000000000 x19: 0x000000014b6a4840 x20: 0xce0f57696add0045 x21: 0x000000010063a5f0 x22: 0x000000014b60f060 x23: 0x0000000000000000 x24: 0x000000014b60f998 x25: 0x0000000000014273 x26: 0x000000014b60f060 x27: 0x000000014b60f060 x28: 0x000000014b80ce00 lr: 0x0000000100d881d8 fp: 0x000000011bb039f0 sp: 0x000000011bb03980 -- C level backtrace information ------------------------------------------- SEGV received in BUS handler [1] 52599 abort ruby test.rb ``` -- https://bugs.ruby-lang.org/

2 3