Ruby Issue Tracking System

09/05/2026

12:08 AM Ruby Bug #22292 (Closed): YJIT/ZJIT: Struct accessor crashes after an instance variable is set on a Struct that exactly fills the largest GC slot

ruby -v: ruby 4.0.6 (2026-07-14 revision 03b6d3f889) +PRISM [x86_64-linux]
Also reproduced on 4.0.1 and on master (3600d410ad, 2026-09-04). Not reproduced on 3.4.9.
## Summary
With YJIT or ZJIT enabled, this sequence crashes the p... shia (Sangyong Sim)

01/09/2024

09:29 AM Ruby Bug #20168 (Closed): Process won't exit when Ractor.select waiting a Ractor

## Reproduction code
```ruby
trap(:INT) do
puts "SIGINT"
exit
end
trap(:TERM) do
puts "SIGTERM"
exit
end
r = Ractor.new do
loop do
sleep 1
end
end
Ractor.select(r) # stucked.
# SIGINT/SIGTERM sent ... shia (Sangyong Sim)

09:08 AM Ruby Bug #20167 (Assigned): Code execution isn't recorded in Ractor

## reproduction code
```ruby
# frozen-string-literal: true
require "coverage"
Coverage.start
require_relative "./some_lib"
# # some_lib.rb
# class C
# def hoge(i)
# i
# end
# end
r = Ractor.new do
loop do... shia (Sangyong Sim)

01/07/2024

01:28 AM Ruby Bug #20146: Code using Ractor with env `RUBY_MAX_CPU=1` ends with unreachable

It seems any shared thread created when max cpu = 1 without enabled_mn_threads.
I suspect native_thread_check_and_create_shared, which always reject create shared thread.
Ref: https://github.com/ruby/ruby/blob/e4a9a73931072458f2bc13b29a... shia (Sangyong Sim)

01/04/2024

02:17 AM Ruby Bug #20146 (Closed): Code using Ractor with env `RUBY_MAX_CPU=1` ends with unreachable

## Reproducible code
```rb
# sample-code.rb
Ractor.new { 1 }
```
```bash
RUBY_MAX_CPU=1 ruby sample-code.rb # This will not end with exit code 0
RUBY_MAX_CPU=2 ruby sample-code.rb # This ends with exit code 0 as expected
```
... shia (Sangyong Sim)

01/01/2024

11:16 PM Ruby Revision 9368782d (git): Use max_cpu when RUBY_MAX_CPU given

shia (Sangyong Sim)

12/11/2018

12:47 AM Ruby Bug #15394: Ruby adds unexpected HTTP header value when using symbol key

Thanks!! shia (Sangyong Sim)

12/10/2018

07:37 AM Ruby Misc #15342: DevelopersMeeting20181212Japan

* [Bug #15394] Ruby adds unexpected HTTP header value when using symbol key
* This is a small change I think, but could make codes less buggy shia (Sangyong Sim)

12/09/2018

05:53 AM Ruby Bug #15394 (Closed): Ruby adds unexpected HTTP header value when using symbol key

## Problem
Because of this, Ruby will set Host header twice if user uses symbol key.
In other words, host header should be set when host header is not given.
See code: https://github.com/ruby/ruby/blob/0777262b1b08722ee99d73fb8c9703... shia (Sangyong Sim)