When running test_descr, I encountered a fatal error!


./python -m test test_descr
0:00:00 load avg: 0.46 Run tests sequentially
0:00:00 load avg: 0.46 [1/1] test_descr
python: Objects/typeobject.c:7318: update_one_slot: Assertion `!PyErr_Occurred()' failed.
Fatal Python error: Aborted

Current thread 0x00007ff22eb72140 (most recent call first):
  File "/home/lubuntu2/cpython/Lib/test/test_descr.py", line 3923 in test_mutable_bases
  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_descr.py", line 5643 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)

This is because update_all_slots() is called immediately after add_all_subclasses() in type_set_bases(). If an exception occurs in add_all_subclasses() (for example, MemoryError), update_all_slots() will be called with a live exception.