[3.13] gh-132942: Fix races in type lookup cache #133114

nascheme · 2025-04-28T21:43:47Z

Two races related to the type lookup cache, when used in the free-threaded build. This caused test_opcache to sometimes fail (as well as other hard to re-produce failures).

Issue: test_opcache fails randomly (failure or crash) #132942

Two races related to the type lookup cache, when used in the free-threaded build. This caused test_opcache to sometimes fail (as well as other hard to re-produce failures).

bedevere-bot · 2025-04-28T22:54:21Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot aarch64 Fedora Stable Clang 3.13 (tier-2) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1456/builds/695) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1456/builds/695

Failed tests:

test_interpreters

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/threading.py", line 1041, in _bootstrap_inner
    self.run()
    ~~~~~~~~^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/threading.py", line 992, in run
    self._target(*self._args, **self._kwargs)
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/test/test_interpreters/test_stress.py", line 47, in run
    interp = interpreters.create()
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/test/support/interpreters/__init__.py", line 76, in create
    id = _interpreters.create(reqrefs=True)
interpreters.InterpreterError: interpreter creation failed
k


Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/threading.py", line 1041, in _bootstrap_inner
    self.run()
    ~~~~~~~~^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/threading.py", line 992, in run
    self._target(*self._args, **self._kwargs)
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/test/test_interpreters/test_stress.py", line 30, in task
    interp = interpreters.create()
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.clang/build/Lib/test/support/interpreters/__init__.py", line 76, in create
    id = _interpreters.create(reqrefs=True)
interpreters.InterpreterError: interpreter creation failed
k

bedevere-bot · 2025-04-28T23:22:15Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x RHEL9 Refleaks 3.13 (tier-3) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1575/builds/743) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1575/builds/743

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-rhel9-s390x.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

bedevere-bot · 2025-04-28T23:25:19Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 RHEL8 Refleaks 3.13 (tier-1) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1385/builds/834) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1385/builds/834

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-RHEL8-x86_64.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

bedevere-bot · 2025-04-28T23:38:35Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 FreeBSD Refleaks 3.13 (tier-3) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1615/builds/703) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1615/builds/703

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/buildbot/buildarea/3.13.ware-freebsd.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

bedevere-bot · 2025-04-29T00:21:57Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Fedora Stable Refleaks 3.13 (tier-1) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1471/builds/729) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1471/builds/729

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-x86_64.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

bedevere-bot · 2025-04-29T00:42:51Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot aarch64 Fedora Stable Refleaks 3.13 (tier-2) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1512/builds/556) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1512/builds/556

Failed tests:

test_descr

Failed subtests:

test_python_calls_appear_in_the_stack_if_perf_activated - test.test_perf_profiler.TestPerfProfilerWithDwarf.test_python_calls_appear_in_the_stack_if_perf_activated
test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base


Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-aarch64.refleak/build/Lib/test/test_perf_profiler.py", line 367, in test_python_calls_appear_in_the_stack_if_perf_activated
    self.assertEqual(stderr, "")
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^
AssertionError: 'Warning:\nProcessed 714 events and lost 3[34 chars]\n\n' != ''
- Warning:
- Processed 714 events and lost 3 chunks!
- 
- Check IO/CPU overload!
-

bedevere-bot · 2025-04-29T00:48:17Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot aarch64 RHEL8 Refleaks 3.13 (tier-2) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1445/builds/595) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1445/builds/595

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-RHEL8-aarch64.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

nascheme · 2025-04-29T02:16:34Z

I believe this has revealed a bug in the unit test that the MRO cache bug was hidding. See gh-133122. The quick fix would be to just disable that unit test.

bedevere-bot · 2025-04-29T02:19:13Z

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot PPC64LE Fedora Stable Refleaks 3.13 (tier-2) has failed when building commit ca46ec8.

What do you need to do:

Don't panic.
Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1467/builds/549) and take a look at the build logs.
Check if the failure is related to this commit (ca46ec8) or if it is a false positive.
If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1467/builds/549

Failed tests:

test_descr

Failed subtests:

test_type_lookup_mro_reference - test.test_descr.MiscTests.test_type_lookup_mro_reference

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.13.cstratak-fedora-stable-ppc64le.refleak/build/Lib/test/test_descr.py", line 5181, in test_type_lookup_mro_reference
    self.assertEqual(X.mykey, 'from Base')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'from Base2' != 'from Base'
- from Base2
?          -
+ from Base

nascheme added type-crash A hard crash of the interpreter, possibly with a core dump 3.13 bugs and security fixes topic-free-threading labels Apr 28, 2025

nascheme requested a review from markshannon as a code owner April 28, 2025 21:43

bedevere-app bot added the awaiting core review label Apr 28, 2025

bedevere-app bot mentioned this pull request Apr 28, 2025

test_opcache fails randomly (failure or crash) #132942

Open

[3.13] pythongh-132942: Fix races in type lookup cache

c551898

Two races related to the type lookup cache, when used in the free-threaded build. This caused test_opcache to sometimes fail (as well as other hard to re-produce failures).

nascheme force-pushed the gh-132942-tp-lookup-race-3.13 branch from d621626 to c551898 Compare April 28, 2025 21:44

nascheme enabled auto-merge (squash) April 28, 2025 21:55

nascheme merged commit ca46ec8 into python:3.13 Apr 28, 2025
37 checks passed

bedevere-app bot removed the awaiting core review label Apr 28, 2025

nascheme mentioned this pull request Apr 29, 2025

Leak test of test_descr fails Base2 != Base #133122

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[3.13] gh-132942: Fix races in type lookup cache #133114

[3.13] gh-132942: Fix races in type lookup cache #133114

nascheme commented Apr 28, 2025 •

edited by bedevere-app bot

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nascheme commented Apr 29, 2025

bedevere-bot commented Apr 29, 2025

[3.13] gh-132942: Fix races in type lookup cache #133114

[3.13] gh-132942: Fix races in type lookup cache #133114

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nascheme commented Apr 28, 2025 • edited by bedevere-app bot Loading

bedevere-bot commented Apr 28, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 28, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 28, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 28, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 29, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 29, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

bedevere-bot commented Apr 29, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

nascheme commented Apr 29, 2025

bedevere-bot commented Apr 29, 2025

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

nascheme commented Apr 28, 2025 •

edited by bedevere-app bot

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