Ruby Issue Tracking System

08/12/2026

09:00 PM Ruby Bug #22243: Change fork behavior when Process._fork raises an exception during fork with a block argument

Thanks for the report. I'm changing this from feature request to bug because this behavior is very surprising and shouldn't happen. luke-gru (Luke Gruber)

05:29 PM Ruby Bug #22242: SEGV in method dispatch (`vm_call_iseq_setup_kwparm_nokwarg` / `def_iseq_ptr`) on Ruby 4.0.6 — Rails CI

Thank you for the report. Has rails ran CI with other 4.0 releases? If so, did you notice any similar crashes for 4.0 releases preceding 4.0.6? luke-gru (Luke Gruber)

08/11/2026

01:18 PM Ruby Bug #22237 (Closed): GC.auto_compact corrupts a String or segfaults from String#tr with dup or gsub

This has been fixed by https://github.com/ruby/ruby/commit/9144c914a1a51176d461c06e11bc78723c2c24cb.
Backport PR is [here](https://github.com/ruby/ruby/pull/18290). luke-gru (Luke Gruber)

01:08 PM Ruby Feature #22238 (Open): String#tr to take a Hash for multi-character replacements

The commit in the previous message has the wrong Issue ID, it is unrelated. luke-gru (Luke Gruber)

08/10/2026

01:44 PM Ruby Bug #22237: GC.auto_compact corrupts a String or segfaults from String#tr with dup or gsub

Thanks for the good repro, it was very helpful. I have a patch [here](https://github.com/ruby/ruby/pull/18277). luke-gru (Luke Gruber)

08/05/2026

06:15 PM Ruby Feature #22227: Per-Ractor GC: collect each Ractor's heap locally, stop the world only when needed

Eregon (Benoit Daloze) wrote in #note-2:
> Is this safe? It's writing concurrently to a shareable object IIUC, and might leave leftover mark bits which might matter for the global GC.
It only marks shareable objects that are in the crea... luke-gru (Luke Gruber)

08/04/2026

09:01 PM Ruby Bug #22225: YJIT regenerates a branch while a duplicate target still points to the invalidated block

I think this is one of those instances I *should* have used an LLM, sorry! It has me thinking that this is not a bug after all. The JIT team will still take a look at it, but this may not be the repro to your bug that you were hoping for. luke-gru (Luke Gruber)

08/03/2026

09:14 PM Ruby Bug #22217: Segmentation fault when resuming execution with `Coverage.start` and ruby/debug

[Backport PR](https://github.com/ruby/ruby/pull/18184). luke-gru (Luke Gruber)

06:57 PM Ruby Bug #22217: Segmentation fault when resuming execution with `Coverage.start` and ruby/debug

Thanks for the report and minimal repro, it was very helpful. I have a [PR](https://github.com/ruby/ruby/pull/18182). This will be fixed in 4.0.7 (released some time in September). The affected version are 4.0.0 - 4.0.6. luke-gru (Luke Gruber)

08:27 PM Ruby Bug #22224: YJIT: rb_yjit_invalidate_ep_is_bp takes the VM lock stopping Ractors on every Proc materialization; multi-Ractor throughput collapses (up to ~150x)

The PR is [here](https://github.com/ruby/ruby/pull/18176). I've also marked this as needing a backport because this really is a bug, it can slow down Ractors a lot. luke-gru (Luke Gruber)