Bug #21203: TestGc#test_gc_parameter_init_slots is flaky results

• Status: Assigned
• Assignee: peterzhu2118 (Peter Zhu)
• Target version: -
• Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[hsbt (Hiroshi SHIBATA)]

I faced TestGc#test_gc_parameter_init_slots failure at everyday.

https://github.com/ruby/ruby/actions/runs/14120822712/job/39560620479

    1) Failure:
  TestGc#test_gc_parameter_init_slots [/home/runner/work/ruby/ruby/src/test/ruby/test_gc.rb:549]:
  <2> expected but was
  <3>.

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to peterzhu2118 (Peter Zhu)

[ono-max (Naoto Ono)]

• Status changed from Assigned to Closed

Applied in changeset git|a671b25525279706d1fa2ee3b25ef45e3ec0eb89.

---

[Bug #21203] Skip TestGc#test_gc_parameter_init_slots since it is flaky (#13025)

https://bugs.ruby-lang.org/issues/21203

TestGc#test_gc_parameter_init_slots is a flaky test that fails intermittently. Until the issue with flakiness is resolved, I will skip it.

[hsbt (Hiroshi SHIBATA)]

• Status changed from Closed to Assigned

[peterzhu2118 (Peter Zhu)]

I can't reproduce this on my ARM macOS or x86 Linux machine with -DVM_CHECK_MODE enabled. Do you know how this can be reproduced?

[mame (Yusuke Endoh)]

@peterzhu2118 (Peter Zhu) Thanks for working on this issue. Because it's a flaky issue, it is difficult to tell how to reproduce it.

According to Launchable, we can see that

• this issue started occuring around 2025-03-17, and
• it occured on ubuntu-22.04 and ubuntu-24.04-arm with -DVM_CHECK_MODE.

https://app.launchableinc.com/organizations/ruby/workspaces/ruby/data/test-paths/file%3Dtest%2Fruby%2Ftest_gc.rb%23%23%23class%3DTestGc%23%23%23testcase%3Dtest_gc_parameter_init_slots?testSessionStatus=fail

I hope it helps.

[hsbt (Hiroshi SHIBATA)]

@peterzhu2118 (Peter Zhu) I could reproduce this only one time with my Apple Silicon macOS.

  1) Failure:
TestGc#test_latest_gc_info_weak_references_count [/Users/hsbt/Documents/github.com/ruby/ruby/test/ruby/test_gc.rb:422]:
Expected 3 to be <= 2.