Python segmentation fault with test_scroll and test_debug

[bnavigator]

Hi,

on openSUSE (not only within the package build system but also when run on a live desktop system) we currently get a segfault after pytest has run all the tests:

[   42s] + cd /home/abuild/rpmbuild/BUILD
[   42s] + cd qtconsole-4.7.7
[   42s] + export QT_QPA_PLATFORM=offscreen
[   42s] + QT_QPA_PLATFORM=offscreen
[   42s] ++ '[' -f _current_flavor ']'
[   42s] ++ cat _current_flavor
[   42s] + python_flavor=python3
[   42s] + '[' -z python3 ']'
[   42s] + '[' python3 '!=' python3 ']'
[   42s] + echo python3
[   42s] + PYTHONPATH=/home/abuild/rpmbuild/BUILDROOT/python-qtconsole-4.7.7-28.1.x86_64/usr/lib/python3.8/site-packages
[   42s] + PYTHONDONTWRITEBYTECODE=1
[   42s] + pytest-3.8 --ignore=_build.python2 --ignore=_build.python3 --ignore=_build.pypy3 -v
[   42s] ============================= test session starts ==============================
[   42s] platform linux -- Python 3.8.5, pytest-6.0.1, py-1.9.0, pluggy-0.13.1 -- /usr/bin/python3
[   42s] cachedir: .pytest_cache
[   42s] PyQt5 5.15.0 -- Qt runtime 5.15.1 -- Qt compiled 5.15.1
[   42s] rootdir: /home/abuild/rpmbuild/BUILD/qtconsole-4.7.7
[   42s] plugins: qt-3.3.0, flaky-3.7.0
[   43s] collecting ... collected 41 items
[   43s] 
[   53s] qtconsole/tests/test_00_console_widget.py::test_scroll[True] PASSED      [  2%]
[   64s] qtconsole/tests/test_00_console_widget.py::test_scroll[False] PASSED     [  4%]
[   68s] qtconsole/tests/test_00_console_widget.py::test_input PASSED             [  7%]
[   74s] qtconsole/tests/test_00_console_widget.py::test_debug PASSED             [  9%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_complete SKIPPED [ 12%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_complete_python SKIPPED [ 14%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_indent SKIPPED [ 17%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_keypresses SKIPPED [ 19%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_link_handling SKIPPED [ 21%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_prompt_cursors SKIPPED [ 24%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_select_all SKIPPED [ 26%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_special_characters SKIPPED [ 29%]
[   74s] qtconsole/tests/test_00_console_widget.py::TestConsoleWidget::test_width_height SKIPPED [ 31%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_backspace PASSED [ 34%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_beep PASSED [ 36%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_carriage_return PASSED [ 39%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_carriage_return_newline PASSED [ 41%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_clear PASSED [ 43%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_colors PASSED [ 46%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_colors_xterm PASSED [ 48%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_combined PASSED [ 51%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_formfeed PASSED [ 53%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_scroll PASSED [ 56%]
[   74s] qtconsole/tests/test_ansi_code_processor.py::TestAnsiCodeProcessor::test_true_color PASSED [ 58%]
[   74s] qtconsole/tests/test_app.py::test_help_output SKIPPED                    [ 60%]
[   74s] qtconsole/tests/test_app.py::test_generate_config SKIPPED                [ 63%]
[   75s] qtconsole/tests/test_comms.py::Tests::test_frontend_to_kernel PASSED     [ 65%]
[   87s] qtconsole/tests/test_comms.py::Tests::test_kernel_to_frontend PASSED     [ 68%]
[   87s] qtconsole/tests/test_completion_widget.py::TestCompletionWidget::test_common_path_complete SKIPPED [ 70%]
[   87s] qtconsole/tests/test_completion_widget.py::TestCompletionWidget::test_droplist_completer_keyboard SKIPPED [ 73%]
[   87s] qtconsole/tests/test_completion_widget.py::TestCompletionWidget::test_droplist_completer_mousepick SKIPPED [ 75%]
[   87s] qtconsole/tests/test_completion_widget.py::TestCompletionWidget::test_droplist_completer_shows SKIPPED [ 78%]
[   87s] qtconsole/tests/test_frontend_widget.py::TestFrontendWidget::test_transform_classic_prompt SKIPPED [ 80%]
[   87s] qtconsole/tests/test_frontend_widget.py::TestFrontendWidget::test_transform_ipy_prompt SKIPPED [ 82%]
[   87s] qtconsole/tests/test_jupyter_widget.py::TestJupyterWidget::test_other_output SKIPPED [ 85%]
[   87s] qtconsole/tests/test_jupyter_widget.py::TestJupyterWidget::test_stylesheet_changed SKIPPED [ 87%]
[   87s] qtconsole/tests/test_kill_ring.py::TestKillRing::test_generic SKIPPED    [ 90%]
[   87s] qtconsole/tests/test_kill_ring.py::TestKillRing::test_qt_basic SKIPPED   [ 92%]
[   87s] qtconsole/tests/test_kill_ring.py::TestKillRing::test_qt_cursor SKIPPED  [ 95%]
[   87s] qtconsole/tests/test_styles.py::TestStyles::test_dark_color PASSED       [ 97%]
[   87s] qtconsole/tests/test_styles.py::TestStyles::test_dark_style PASSED       [100%]
[   87s] 
[   87s] =============================== warnings summary ===============================
[   87s] qtconsole/ansi_code_processor.py:47
[   87s]   /home/abuild/rpmbuild/BUILD/qtconsole-4.7.7/qtconsole/ansi_code_processor.py:47: DeprecationWarning: invalid escape sequence \[
[   87s]     CSI_SUBPATTERN = '\[(.*?)([%s])' % CSI_COMMANDS
[   87s] 
[   87s] qtconsole/ansi_code_processor.py:48
[   87s]   /home/abuild/rpmbuild/BUILD/qtconsole-4.7.7/qtconsole/ansi_code_processor.py:48: DeprecationWarning: invalid escape sequence \]
[   87s]     OSC_SUBPATTERN = '\](.*?)[\x07\x1b]'
[   87s] 
[   87s] qtconsole/tests/test_00_console_widget.py::test_scroll[True]
[   87s]   /usr/lib/python3.8/site-packages/jupyter_client/threaded.py:182: DeprecationWarning: zmq.eventloop.ioloop is deprecated in pyzmq 17. pyzmq now works with default tornado and asyncio eventloops.
[   87s]     self.ioloop = ioloop.IOLoop()
[   87s] 
[   87s] qtconsole/tests/test_comms.py::Tests::test_frontend_to_kernel
[   87s]   /usr/lib/python3.8/site-packages/traitlets/config/configurable.py:73: DeprecationWarning: Passing unrecoginized arguments to super(BlockingKernelClient).__init__(signature_scheme='hmac-sha256', key=b'7e9d4082-71e107ee180feb851c6b954c').
[   87s]   object.__init__() takes exactly one argument (the instance to initialize)
[   87s]   This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
[   87s]     super(Configurable, self).__init__(**kwargs)
[   87s] 
[   87s] qtconsole/tests/test_comms.py::Tests::test_kernel_to_frontend
[   87s]   /usr/lib/python3.8/site-packages/traitlets/config/configurable.py:73: DeprecationWarning: Passing unrecoginized arguments to super(BlockingKernelClient).__init__(signature_scheme='hmac-sha256', key=b'31573c52-3dfeda1a0115572a97f46a63').
[   87s]   object.__init__() takes exactly one argument (the instance to initialize)
[   87s]   This is deprecated in traitlets 4.2.This error will be raised in a future release of traitlets.
[   87s]     super(Configurable, self).__init__(**kwargs)
[   87s] 
[   87s] -- Docs: https://docs.pytest.org/en/stable/warnings.html
[   87s] ===Flaky Test Report===
[   87s] 
[   87s] test_scroll[True] passed 1 out of the required 1 times. Success!
[   87s] test_scroll[False] passed 1 out of the required 1 times. Success!
[   87s] test_input passed 1 out of the required 1 times. Success!
[   87s] test_debug passed 1 out of the required 1 times. Success!
[   87s] 
[   87s] ===End Flaky Test Report===
[   87s] ================= 19 passed, 22 skipped, 5 warnings in 44.81s ==================
[   87s] Fatal Python error: Segmentation fault
[   87s] 
[   87s] Thread 0x00007fe4fb7fe700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/threading.py", line 306 in wait
[   87s]   File "/usr/lib64/python3.8/threading.py", line 558 in wait
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 161 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Thread 0x00007fe5117fa700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/threading.py", line 306 in wait
[   87s]   File "/usr/lib64/python3.8/threading.py", line 558 in wait
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 161 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Thread 0x00007fe512ffd700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/selectors.py", line 468 in select
[   87s]   File "/usr/lib64/python3.8/asyncio/base_events.py", line 1823 in _run_once
[   87s]   File "/usr/lib64/python3.8/asyncio/base_events.py", line 570 in run_forever
[   87s]   File "/usr/lib64/python3.8/site-packages/tornado/platform/asyncio.py", line 149 in start
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/threaded.py", line 187 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Thread 0x00007fe5137fe700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/site-packages/zmq/sugar/poll.py", line 103 in poll
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 115 in _poll
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 153 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Thread 0x00007fe5297fa700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/site-packages/zmq/sugar/poll.py", line 103 in poll
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 115 in _poll
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/channels.py", line 153 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Thread 0x00007fe52a7fc700 (most recent call first):
[   87s]   File "/usr/lib64/python3.8/selectors.py", line 468 in select
[   87s]   File "/usr/lib64/python3.8/asyncio/base_events.py", line 1823 in _run_once
[   87s]   File "/usr/lib64/python3.8/asyncio/base_events.py", line 570 in run_forever
[   87s]   File "/usr/lib64/python3.8/site-packages/tornado/platform/asyncio.py", line 149 in start
[   87s]   File "/usr/lib/python3.8/site-packages/jupyter_client/threaded.py", line 187 in run
[   87s]   File "/usr/lib64/python3.8/threading.py", line 932 in _bootstrap_inner
[   87s]   File "/usr/lib64/python3.8/threading.py", line 890 in _bootstrap
[   87s] 
[   87s] Current thread 0x00007fe554955740 (most recent call first):
[   87s] <no Python frame>
[   87s] /var/tmp/rpm-tmp.vJIam6: line 39:  2043 Segmentation fault      PYTHONPATH=${PYTHONPATH:+$PYTHONPATH:}/home/abuild/rpmbuild/BUILDROOT/python-qtconsole-4.7.7-28.1.x86_64/usr/lib/python3.8/site-packages PYTHONDONTWRITEBYTECODE=1 pytest-3.8 --ignore=_build.python2 --ignore=_build.python3 --ignore=_build.pypy3 -v
[   87s] error: Bad exit status from /var/tmp/rpm-tmp.vJIam6 (%check)

The segfault goes away when skipping BOTH test_scroll and test_debug from test_00_console_widget.py. Only skipping one of the debug= parametrizations or the individual tests does not help.