From: "yahonda (Yasuo Honda) via ruby-core" <ruby-core@...>
Date: 2026-08-27T02:01:21+00:00
Subject: [ruby-core:126510] [Ruby Bug#22173] `Ractor.new { Fiber.current }.value` raises `[BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2`

Issue #22173 has been updated by yahonda (Yasuo Honda).


This assertion failure does not reproduce since https://github.com/ruby/ruby/commit/09aab7899fa0d0014e458c319e689175881a2075 so I think we can close it.

----------------------------------------
Bug #22173: `Ractor.new { Fiber.current }.value` raises `[BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2` 
https://bugs.ruby-lang.org/issues/22173#change-118670

* Author: yahonda (Yasuo Honda)
* Status: Open
* Assignee: ractor
* ruby -v: ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
* Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN
----------------------------------------
This issue is originally found at https://github.com/rails/rails/issues/57954

### Steps to reproduce

1. Build ruby with `-DRUBY_DEBUG=1` enabled like

```
#!/bin/bash

cd ${HOME}/src/github.com/ruby/ruby
make clean
make distclean
make realclean
./autogen.sh
./configure --prefix="${HOME}/.local/share/mise/installs/ruby/trunk" cppflags="-DENABLE_PATH_CHECK=0 -DRUBY_DEBUG=1" optflags="-O3 -fno-inline" --disable-install-doc
make -j"$(getconf _NPROCESSORS_ONLN)"
make install
```

2. Run these one liners

```
ruby -ve 'Ractor.new { Fiber.current }.value'
```

```
ruby -ve 'Fiber[:x] = Object.new; Ractor.new { Fiber[:x].class }.value'
```

### Expected behavior
Both of one liners should pass:

```
$ ruby -ve 'Ractor.new { Fiber.current }.value'
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
-e:1: warning: Ractor API is experimental and may change in future versions of Ruby.
$ ruby -ve 'Fiber[:x] = Object.new; Ractor.new { Fiber[:x].class }.value'
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
-e:1: warning: Ractor API is experimental and may change in future versions of Ruby.
```

### Actual behavior
Both of them raise the `[BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2` assertion failures added through https://github.com/ruby/ruby/commit/af2471365fe

```
$ ruby -ve 'Ractor.new { Fiber.current }.value'
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
-e:1: warning: Ractor API is experimental and may change in future versions of Ruby.
<OBJ_INFO:rb_ractor_confirm_belonging@ractor_core.h:329> 0x000078fa403213d0 fiber/Fiber
-e:1: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
...
```

```
$ ruby -ve 'Fiber[:x] = Object.new; Ractor.new { Fiber[:x].class }.value'
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
-e:1: warning: Ractor API is experimental and may change in future versions of Ruby.
<OBJ_INFO:rb_ractor_confirm_belonging@ractor_core.h:329> 0x00007e56dbe9dfa8 T_OBJECT/Object len:0 capa:2 ptr:0x00007e56dbe9dfb8
-e:1: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2
ruby 4.1.0dev (2026-07-02T09:24:35Z master 7c69f93d53) +PRISM [x86_64-linux]
```



---Files--------------------------------
1.out (23.8 KB)
2.out (23.8 KB)


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