Ruby Issue Tracking System

03/10/2026

08:27 PM Ruby Bug #21926: Thread#value on popen3 wait thread hangs in finalizer

A note to whoever backports this (which could be me, I'm just waiting ~ 1 week and checking various CIs after the merge):
https://github.com/ruby/ruby/pull/16362 should be backported as well, they are really 1 fix in 2 separate commit... luke-gru (Luke Gruber)

03/09/2026

05:29 PM Ruby Bug #21876 (Third Party's Issue): Addrinfo.getaddrinfo(AF_UNSPEC) deadlocks after fork on macOS for IPv4-only hosts

luke-gru (Luke Gruber)

05:16 PM Ruby Bug #21876: Addrinfo.getaddrinfo(AF_UNSPEC) deadlocks after fork on macOS for IPv4-only hosts

I'm getting a segfault when running your minimal reproduction script on my Macbook Pro (`Darwin Mac 25.2.0 Darwin Kernel Version 25.2.0 (Apple Silicon)`).
I get the segfault when compiling under all 3 `GETADDRINFO_IMPL` implementations ... luke-gru (Luke Gruber)

03/06/2026

03:27 PM Ruby Bug #21873: `UnboundMethod#==` returns false for methods from included/extended modules

3.4 backport PR: https://github.com/ruby/ruby/pull/16326 luke-gru (Luke Gruber)

03/05/2026

07:37 PM Ruby Bug #21926: Thread#value on popen3 wait thread hangs in finalizer

Thank you for the nice reproduction! We have a fix coming, and it will probably be backported to 3.3, 3.4 and 4.0.
The fix is at https://github.com/ruby/ruby/pull/16307. luke-gru (Luke Gruber)

01/29/2026

02:26 PM Ruby Bug #21840 (Open): Locking a mutex can lead to starvation

I wasn't aware of those old issues. I'll take a look, thanks!
I reverted the commit because of issues with a `Monitor` test in CI. I thought it was related to this change, but the test kept failing even after the revert. It turns out it... luke-gru (Luke Gruber)

01/22/2026

07:30 PM Ruby Bug #21836: RUBY_MN_THREADS deadlock and sleep issues

I'm confused about what should happen. Shouldn't it return roughly after 1 second instead of 10 seconds? I'll look into the sleep issue with `RUBY_MN_THREADS=1`, but I can't reproduce the deadlock or segfault with a more recent commit (a... luke-gru (Luke Gruber)

07:13 PM Ruby Bug #21685: Unnecessary context-switching, especially bad on multi-core machines.

I did some benchmarking based on the updated solution (https://github.com/ruby/ruby/pull/15840). I've attached Puma benchmark results that I got using the PR from the previous post (d7ef5ecc9b) vs that PR's base commit (ad6b85450d). The ... luke-gru (Luke Gruber)

01/19/2026

09:02 PM Ruby Feature #21843 (Open): Simple Priority Scheduler

Hi,
There's a problem with Ruby's scheduler that I want to solve.
# The Problem
Since Ruby schedules threads using round-robin inside a Ractor, threads doing I/O after only running for a short time are punished. Once the I/O fin... luke-gru (Luke Gruber)

01/15/2026

06:56 PM Ruby Bug #21840 (Open): Locking a mutex can lead to starvation

Continually locking a mutex `m` can lead to starvation if all other threads are on the waitq of `m`.
Let `T` be the thread that keeps on acquiring mutex `m` in a loop.
Iteration 1:
1) `T` locks mutex `m`
2) All other threads at... luke-gru (Luke Gruber)