$ ./python -m test -v test_sys_settrace test_pdb
...
test_pdb_breakpoints_preserved_across_interactive_sessions (test.test_pdb)
Doctest: test.test_pdb.test_pdb_breakpoints_preserved_across_interactive_sessions ... python: Python/instrumentation.c:1293: _Py_call_instrumentation_instruction: Assertion `next_opcode != 0' failed.
Fatal Python error: Aborted

Current thread 0x00007fba31132740 (most recent call first):
  File "<string>", line 1 in <module>
  File "/home/serhiy/py/cpython/Lib/bdb.py", line 600 in run
  File "/home/serhiy/py/cpython/Lib/pdb.py", line 1962 in run
  File "<doctest test.test_pdb.test_pdb_breakpoints_preserved_across_interactive_sessions[3]>", line 7 in <module>
  File "/home/serhiy/py/cpython/Lib/doctest.py", line 1374 in __run
  File "/home/serhiy/py/cpython/Lib/doctest.py", line 1524 in run
  File "/home/serhiy/py/cpython/Lib/doctest.py", line 2244 in runTest
  File "/home/serhiy/py/cpython/Lib/unittest/case.py", line 589 in _callTestMethod
  File "/home/serhiy/py/cpython/Lib/unittest/case.py", line 634 in run
  File "/home/serhiy/py/cpython/Lib/unittest/case.py", line 690 in __call__
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 122 in run
  File "/home/serhiy/py/cpython/Lib/unittest/suite.py", line 84 in __call__
  File "/home/serhiy/py/cpython/Lib/unittest/runner.py", line 240 in run
  File "/home/serhiy/py/cpython/Lib/test/support/__init__.py", line 1142 in _run_suite
  File "/home/serhiy/py/cpython/Lib/test/support/__init__.py", line 1269 in run_unittest
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 393 in run_unittest
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 447 in test_func
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 407 in regrtest_runner
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 451 in _load_run_test
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 491 in _runtest_env_changed_exc
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 348 in _runtest
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/runtest.py", line 375 in runtest
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 462 in run_test
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 495 in run_tests_sequentially
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 632 in run_tests
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 855 in action_run_tests
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 883 in _main
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 822 in main
  File "/home/serhiy/py/cpython/Lib/test/libregrtest/main.py", line 891 in main
  File "/home/serhiy/py/cpython/Lib/test/__main__.py", line 2 in <module>
  File "/home/serhiy/py/cpython/Lib/runpy.py", line 88 in _run_code
  File "/home/serhiy/py/cpython/Lib/runpy.py", line 198 in _run_module_as_main