When running test_pickle, I sometimes see an assertion failure.

./python -m test test_pickle
0:00:00 load avg: 1.04 Run tests sequentially
0:00:00 load avg: 1.04 [1/1] test_pickle
python: Objects/typeobject.c:3151: _PyType_Lookup: Assertion `!PyErr_Occurred()' failed.
Fatal Python error: Aborted

Current thread 0x00007f8158632140 (most recent call first):
  File "/home/lubuntu2/cpython/Lib/test/pickletester.py", line 3400 in test_unpickling_buffering_readline
  File "/home/lubuntu2/cpython/Lib/unittest/case.py", line 617 in _callTestMethod
  File "/home/lubuntu2/cpython/Lib/unittest/case.py", line 663 in run
  File "/home/lubuntu2/cpython/Lib/unittest/case.py", line 725 in __call__
  File "/home/lubuntu2/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/lubuntu2/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/lubuntu2/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/lubuntu2/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/lubuntu2/cpython/Lib/test/support/testresult.py", line 162 in run
  File "/home/lubuntu2/cpython/Lib/test/support/__init__.py", line 2032 in _run_suite
  File "/home/lubuntu2/cpython/Lib/test/support/__init__.py", line 2128 in run_unittest
  File "/home/lubuntu2/cpython/Lib/test/test_pickle.py", line 525 in test_main
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/runtest.py", line 234 in _runtest_inner2
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/runtest.py", line 270 in _runtest_inner
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/runtest.py", line 153 in _runtest
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/runtest.py", line 193 in runtest
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/main.py", line 417 in run_tests_sequential
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/main.py", line 515 in run_tests
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/main.py", line 687 in _main
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/main.py", line 634 in main
  File "/home/lubuntu2/cpython/Lib/test/libregrtest/main.py", line 712 in main
  File "/home/lubuntu2/cpython/Lib/test/__main__.py", line 2 in <module>
  File "/home/lubuntu2/cpython/Lib/runpy.py", line 85 in _run_code
  File "/home/lubuntu2/cpython/Lib/runpy.py", line 192 in _run_module_as_main
Aborted (core dumped)


In _Unpickler_SetInputStream(), _PyObject_LookupAttrId() is called three times in a row without any error handling.
If an exception occurs during the first or second call, _PyObject_LookupAttrId() will be called with a live exception.

I do not understand how you got an assertion failure. Did you interrupt tests with Ctrl-C?

Good catch on this, Zackery!

For anyone readying this, Serhiy posted a minimal reproducer in a PR comment, and the PR now adds a test for this.

Reproduced on 3.11 with Serhiy's reproducer: 

class F:
    @property
    def read(self):
        1/0

import pickle
pickle.load(F())