[New-bugs-announce] [issue35961] gc_decref: Assertion "gc_get_refs(g) > 0" failed: refcount is too small

[Pablo Galindo Salgado]

New submission from Pablo Galindo Salgado <pablogsal at gmail.com>:

I am seeing some failures in travis and some buildbots:

0:02:24 load avg: 3.30 [147/420/1] test_slice crashed (Exit code -6) -- running: test_multiprocessing_spawn (32 sec 523 ms), test_asyncio (45 sec 433 ms), test_multiprocessing_forkserver (47 sec 869 ms)
Modules/gcmodule.c:110: gc_decref: Assertion "gc_get_refs(g) > 0" failed: refcount is too small
Enable tracemalloc to get the memory block allocation traceback
object  : <test.test_slice.SliceTest.test_cmp.<locals>.BadCmp object at 0x2ab2051faef0>
type    : BadCmp
refcount: 1
address : 0x2ab2051faef0
Fatal Python error: _PyObject_AssertFailed
Current thread 0x00002ab1fe0519c0 (most recent call first):
  File "/home/travis/build/python/cpython/Lib/test/test_slice.py", line 107 in <lambda>
  File "/home/travis/build/python/cpython/Lib/unittest/case.py", line 197 in handle
  File "/home/travis/build/python/cpython/Lib/unittest/case.py", line 782 in assertRaises
  File "/home/travis/build/python/cpython/Lib/test/test_slice.py", line 107 in test_cmp
  File "/home/travis/build/python/cpython/Lib/unittest/case.py", line 642 in run
  File "/home/travis/build/python/cpython/Lib/unittest/case.py", line 702 in __call__
  File "/home/travis/build/python/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/travis/build/python/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/travis/build/python/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/travis/build/python/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/travis/build/python/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/travis/build/python/cpython/Lib/unittest/runner.py", line 176 in run
  File "/home/travis/build/python/cpython/Lib/test/support/__init__.py", line 1935 in _run_suite
  File "/home/travis/build/python/cpython/Lib/test/support/__init__.py", line 2031 in run_unittest
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/runtest.py", line 178 in test_runner
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/runtest.py", line 182 in runtest_inner
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/runtest.py", line 127 in runtest
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/runtest_mp.py", line 68 in run_tests_worker
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/main.py", line 600 in _main
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/main.py", line 586 in main
  File "/home/travis/build/python/cpython/Lib/test/libregrtest/main.py", line 640 in main
  File "/home/travis/build/python/cpython/Lib/test/regrtest.py", line 46 in _main
  File "/home/travis/build/python/cpython/Lib/test/regrtest.py", line 50 in <module>
  File "/home/travis/build/python/cpython/Lib/runpy.py", line 85 in _run_code

Usually, this happens with test_slice but when the test runner runs test_slice in isolation, it succeeds.

I am afraid that this will be a weird combination of tests.

----------
components: Tests
messages: 335185
nosy: pablogsal
priority: normal
severity: normal
status: open
title: gc_decref: Assertion "gc_get_refs(g) > 0" failed: refcount is too small
versions: Python 3.8

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue35961>
_______________________________________