Ruby Issue Tracking System

10/15/2026

03:51 PM Ruby Bug #22406: Process.fork can leave the child unable to resolve hostnames: getaddrinfo helper threads take glibc's resolver lock after releasing the fork lock

Like @byroot, I don't think Ruby explicitly supports extensions calling fork(2) directly. In practice, since 3.4 an extension cannot fork safely anyway: it cannot take the fork lock before fork(2) or reset it in the child (`rb_thread_acq... mame (Yusuke Endoh)

05:03 AM Ruby Bug #22439 (Closed): Segfault in `Thread::Backtrace::Location#syntax_tree` (via `Exception#detailed_message` / error_highlight) when called from multiple Ractors

Thank you for confirming the patches! I think this is resolved, so I'm closing this ticket. mame (Yusuke Endoh)

05:02 AM Ruby Bug #22440 (Closed): Referencing an autoload constant from multiple Ractors dumps core

Applied in changeset commit:git|8a060f90ba36441cfeb509eacb10f609314f5bfe.
----------
Fix SEGV when referencing an autoload constant from multiple Ractors
vm_ic_update used GET_RACTOR() after the constant lookup. The lookup may
block wa... mame (Yusuke Endoh)

05:01 AM Ruby Revision 8a060f90 (git): Fix SEGV when referencing an autoload constant from multiple Ractors

vm_ic_update used GET_RACTOR() after the constant lookup. The lookup may
block waiting for an autoload, and under the M:N thread scheduler the
thread may then be resumed on a different native thread. Since
vm_ic_update is inlined into rb... mame (Yusuke Endoh)

04:50 AM Ruby Bug #22442 (Closed): Lazy loading of error_highlight etc. is skipped in threads and Ractors

Applied in changeset commit:git|d193fd3217a87b1015b73a4d31c0f6e116bc3cdd.
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Load the error decoration gems by firing their autoloads
The lazy loading of error_highlight, did_you_mean, and syntax_suggest
claimed the load by an ... mame (Yusuke Endoh)

04:50 AM Ruby Revision d193fd32 (git): Load the error decoration gems by firing their autoloads

The lazy loading of error_highlight, did_you_mean, and syntax_suggest
claimed the load by an atomic exchange before the load started. So a
caller in another Ractor or thread during the load returned the
undecorated message without waitin... mame (Yusuke Endoh)

03:53 AM Ruby Revision c4eadc74 (git): [ruby/rubygems] Rescue the LoadError in the spec for nested bundle exec with monkeypatches

The spec checks that the Kernel.require monkeypatch is still used, by
comparing the whole stdout. However, the script ended with an uncaught
LoadError for the non-existent "foo", and Ruby lazily loads
error_highlight, did_you_mean, and s... mame (Yusuke Endoh)

02:47 AM Ruby Feature #22437: Speed up creation and basic operations of Struct / Data

Thank you for working on this.
As I understand it, experiment/struct-data-core speeds up Struct/Data without breaking compatibility. It will need careful review, but I have no objection to the direction.
Personally, I'm much more i... mame (Yusuke Endoh)

10/14/2026

07:34 PM Ruby Bug #22439: Segfault in `Thread::Backtrace::Location#syntax_tree` (via `Exception#detailed_message` / error_highlight) when called from multiple Ractors

Thank you for the report!
I could reproduce the SEGV only with GCC 16 (GCC 13 and 15 did not reproduce it). Are you also using GCC 16 to build Ruby?
This ticket contained two different problems, so I have split it into:
* #22440... mame (Yusuke Endoh)

07:31 PM Ruby Bug #22442 (Closed): Lazy loading of error_highlight etc. is skipped in threads and Ractors

#21951 made error_highlight / did_you_mean / syntax_suggest lazily loaded.
When the lazy loading is triggered concurrently from threads or Ractors, the decoration may be skipped.
```ruby
# repro.rb
rs = 2.times.map do
Ractor.new... mame (Yusuke Endoh)