Bug #21355: `csv/test/csv/interface/test_read.rb` at test-bundled-gems is flaky recent days

• Status: Assigned
• Assignee: ractor
• Target version: -
• Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[hsbt (Hiroshi SHIBATA)]

I faced test failure of make test-bundled-gems in GitHub Actions. It caused by csv testing with Ractor.

https://github.com/ruby/ruby/actions/runs/15156308046/job/42611877817?pr=13391#step:9:697

 /home/runner/work/ruby/ruby/src/gems/src/csv/test/csv/interface/test_read.rb:56: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.
  <OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:370> (File)
  /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:3
  ruby 3.5.0dev (2025-05-21T07:35:21Z pull/13391/merge 7c1f3e8f7e) [x86_64-linux]

[hsbt (Hiroshi SHIBATA)]

• Status changed from Open to Assigned
• Assignee set to ractor

This issue happened with not only csv tests.

https://github.com/ruby/ruby/actions/runs/14582713974/job/40902544946?pr=13146#step:12:856

<OBJ_INFO:rb_ractor_confirm_belonging@../src/ractor_core.h:374> (File)
  /home/runner/work/ruby/ruby/src/lib/tempfile.rb:387: [BUG] rb_ractor_confirm_belonging object-ractor id:1, current-ractor id:2
  ruby 3.5.0dev (2025-04-21T22:39:55Z pull/13146/merge 8f670373ad) +PRISM [x86_64-linux]