ErrorReporting.handle_exception: causes segfault

##### Orange version

```
orange-canvas-core 0.1.32.dev0
orange-widget-base 4.22.0.dev0+ebc5230
Orange3 3.36.0.dev0+92d84ee
```

Qt related packages

```
AnyQt 0.2.0
PyQt5 5.15.9
PyQt5-Qt5 5.15.2
PyQt5-sip 12.11.0
pyqtgraph 0.13.1
PyQtWebEngine 5.15.6
PyQtWebEngine-Qt5 5.15.2
qtconsole 5.3.2
QtPy 2.2.1
sphinxcontrib-qthelp 1.0.3
```

It also happens in our production environment which has

```
orange-canvas-core 0.1.31
orange-widget-base 4.21.0
Orange3 3.35.0

AnyQt 0.2.0
PyQt5 5.14.1
pyqtgraph 0.13.3
qtconsole 5.4.3
QtPy 2.3.1
```

OS: Ubuntu 20.04

##### Issue description

I have a particular case where an error in `qt.Thread` causes `ErrorReporting.handle_exception` to segfault.

If I replace this

```python
def handle_exception(exc):
return ErrorReporting.handle_exception(exc)
```

with this I don't get the segfault (i.e. the exception gets printed and the app keeps running)

```python
def handle_exception(exc):
traceback.print_exception(*exc)
```

This is the traceback I got from the core dump:

```
(gdb) py-bt-full
#20
#25 Frame 0x5635469acc10, for file /home/denolf/dev/orange-widget-base/orangewidget/workflow/errorreporting.py, line 1555, in handle_exception (cls=, exc=(, ValueError('Array passed to NMF (input W) is full of zeros.',), ), etype=, evalue=(...), tb=, exception='ValueError: Array passed to NMF (input W) is full of zeros.', stacktrace='Traceback (most recent call last):\n File "/home/denolf/dev/darfix/src/darfix/gui/operationThread.py", line 32, in run\n self.data = self.func(*self.args, **self.kwargs)\n File "/home/denolf/dev/darfix/src/darfix/core/dataset.py", line 1632, in nica_nmf\n return self.nmf(\n File "/home/denolf/dev/darfix/src/darfix/core/dataset.py", line 1591, in nmf\n W = model.fit_transform(X, W=W, H=H)\n File "/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/sklearn/decomposition/_nmf...(truncated)
#30 Frame 0x5635461db010, for file /users/denolf/.pyenv/ubuntu_20_04/versions/3.8.5/lib/python3.8/unittest/mock.py, line 1581, in patched (args=(, (, ValueError('Array passed to NMF (input W) is full of zeros.',), )), keywargs={}, newargs=(...), newkeywargs={...})
spec_set, autospec, new_callable, kwargs
#37 Frame 0x7f65e3e5a520, for file /home/denolf/dev/orange-widget-base/orangewidget/workflow/errorreporting.py, line 279, in handle_exception (exc=(, ValueError('Array passed to NMF (input W) is full of zeros.',), ))
traceback.print_exception(*exc)
#58
#63 Frame 0x7f65e365eb20, for file /home/denolf/dev/orange-canvas-core/orangecanvas/application/application.py, line 170, in exec (self=)
return super().exec()
#70 Frame 0x56353e1bb710, for file /home/denolf/dev/orange-canvas-core/orangecanvas/main.py, line 233, in run (self=, arguments=['/users/denolf/projects/workflows/darfix/Augusts2023_BlindSourceIssue_Wzeroes_LIGHT.ows'], config=, stack=) at remote 0x7f6658161df0>, application=, _update_check=None, _send_stat=, _pull_notifs=, output=, _TerminalTextDocument__streams=[(, arguments=['/users/denolf/projects/workflows/darfix/Augusts2023_BlindSourceIssue_Wzeroes_LIGHT.ows'], config=, stack=) at remote 0x7f6658161df0>, application=, _update_check=None, _send_stat=, _pull_notifs=, output=, _TerminalTextDocument__streams=[(, 'store': , 'store_const': , 'store_true': , 'store_false': , 'append': , 'append_const': , 'count': , 'help': , 'version': , 'parsers': , 'extend': }, 'type': {None: }}, _actions...(truncated)
#91 Frame 0x7f668d9d6440, for file /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas, line 8, in ()
sys.exit(main())

(gdb) bt
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007f668e232859 in __GI_abort () at abort.c:79
#2 0x00007f668ccc59bc in qErrnoWarning(char const*, ...) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#3 0x00007f668d4eb437 in () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#4 0x00007f668d66088d in PyQtSlotProxy::unislot(void**) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#5 0x00007f668d661317 in PyQtSlotProxy::qt_metacall(QMetaObject::Call, int, void**) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#6 0x00007f668ceffda3 in QObject::event(QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#7 0x00007f668989c43c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Widgets.so.5
#8 0x00007f66898a2f20 in QApplication::notify(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Widgets.so.5
#9 0x00007f668a3920d6 in sipQApplication::notify(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtWidgets.abi3.so
#10 0x00007f668ced0808 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#11 0x00007f668ced3882 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#12 0x00007f668cf2cb33 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#13 0x00007f668a70717d in g_main_context_dispatch () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007f668a707400 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007f668a7074a3 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007f668cf2c1cc in QEventDispatcherGlib::processEvents(QFlags) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#17 0x00007f668cecf21a in QEventLoop::exec(QFlags) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#18 0x00007f6689a84ff7 in QDialog::exec() () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Widgets.so.5
#19 0x00007f668a2b56b8 in meth_QDialog_exec () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtWidgets.abi3.so
#20 0x00007f668e4c2d97 in cfunction_call_varargs (func=, args=, kwargs=) at Objects/call.c:757
#21 0x00007f668e4c349b in _PyObject_MakeTpCall (callable=, args=, nargs=, keywords=0x0) at Objects/call.c:159
#22 0x00007f668e496533 in _PyObject_Vectorcall (kwnames=0x0, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:125
#23 _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:115
#24 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff90730d90, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#25 0x00007f668e49deca in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3469
#26 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'orangewidget.workflow.errorreporting', '__doc__': None, '__package__': 'orangewidget.workflow', '__loader__': , '__spec__': , origin='/home/denolf/dev/orange-widget-base/orangewidget/workflow/errorreporting.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/home/denolf/dev/orange-widget-base/orangewidget/workflow/__pycache__/errorreporting.cpython-38.pyc', _initializing=False) at remote 0x7f665672b070>, '__file__': '/home/denolf/dev/orange-widget-base/orangewidget/workflow/errorreporting.py', '__cached__': '/home/denolf/dev/orange-widget-base/orangewidget/workflow/__pycache__/errorreporting.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNoteworthy:...(truncated), locals=locals@entry=0x0, args=, argcount=2, kwnames=0x0, kwargs=0x7f65e4506ca8, kwcount=0, kwstep=1, defs=0x0, defcount=0, kwdefs=0x0, closure=0x0, name='handle_exception', qualname='ErrorReporting.handle_exception')
at Python/ceval.c:4298
#27 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=func@entry=, stack=, nargsf=nargsf@entry=2, kwnames=) at Objects/call.c:435
#28 0x00007f668e4c52d3 in PyVectorcall_Call (callable=, tuple=, kwargs=) at Objects/call.c:199
#29 0x00007f668e4976bf in do_call_core
(kwdict={}, callargs=(, (, ValueError('Array passed to NMF (input W) is full of zeros.',), )), func=, tstate=0x56353b103bb0) at Python/ceval.c:5010
#30 _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3559
#31 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'unittest.mock', '__doc__': None, '__package__': 'unittest', '__loader__': , '__spec__': , origin='/users/denolf/.pyenv/ubuntu_20_04/versions/3.8.5/lib/python3.8/unittest/mock.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/users/denolf/.pyenv/ubuntu_20_04/versions/3.8.5/lib/python3.8/unittest/__pycache__/mock.cpython-38.pyc', _initializing=False) at remote 0x7f6668688100>, '__file__': '/users/denolf/.pyenv/ubuntu_20_04/versions/3.8.5/lib/python3.8/unittest/mock.py', '__cached__': '/users/denolf/.pyenv/ubuntu_20_04/versions/3.8.5/lib/python3.8/unittest/__pycache__/mock.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNoteworthy: None is the `nil' object; Ellipsis represents `...' in slices...(truncated), locals=locals@entry=0x0, args=, argcount=2, kwnames=0x0, kwargs=0x7f65e3e5a6a8, kwcount=0, kwstep=1, defs=0x0, defcount=0, kwdefs=0x0, closure=(, , ), name='handle_exception', qualname='ErrorReporting.handle_exception') at Python/ceval.c:4298
#32 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=, stack=, nargsf=, kwnames=) at Objects/call.c:435
#33 0x00007f668e4c6c0a in _PyObject_Vectorcall (kwnames=0x0, nargsf=2, args=0x7f65e3e5a698, callable=) at ./Include/cpython/abstract.h:127
#34 method_vectorcall (method=, args=0x7f65e3e5a6a0, nargsf=, kwnames=0x0) at Objects/classobject.c:60
#35 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#36 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff907313a0, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#37 0x00007f668e49deca in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3469
#38 0x00007f668e49517b in function_code_fastcall (co=, args=, nargs=1, globals=) at Objects/call.c:283
#39 0x00007f668e4c52d3 in PyVectorcall_Call (callable=, tuple=, kwargs=) at Objects/call.c:199
#40 0x00007f668d6600b0 in PyQtSlot::call(_object*, _object*) const () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#41 0x00007f668d660558 in PyQtSlot::invoke(void**, _object*, void*, bool) const () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#42 0x00007f668d66084e in PyQtSlotProxy::unislot(void**) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#43 0x00007f668d661317 in PyQtSlotProxy::qt_metacall(QMetaObject::Call, int, void**) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtCore.abi3.so
#44 0x00007f668ceffda3 in QObject::event(QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#45 0x00007f668989c43c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Widgets.so.5
#46 0x00007f66898a2f20 in QApplication::notify(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Widgets.so.5
#47 0x00007f668a3920d6 in sipQApplication::notify(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtWidgets.abi3.so
#48 0x00007f668ced0808 in QCoreApplication::notifyInternal2(QObject*, QEvent*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#49 0x00007f668ced3882 in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#50 0x00007f668cf2cb33 in postEventSourceDispatch(_GSource*, int (*)(void*), void*) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#51 0x00007f668a70717d in g_main_context_dispatch () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#52 0x00007f668a707400 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#53 0x00007f668a7074a3 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#54 0x00007f668cf2c1cc in QEventDispatcherGlib::processEvents(QFlags) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#55 0x00007f668cecf21a in QEventLoop::exec(QFlags) () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#56 0x00007f668ced81d3 in QCoreApplication::exec() () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/Qt5/lib/libQt5Core.so.5
#57 0x00007f668a1ddcc1 in meth_QApplication_exec () at /users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/lib/python3.8/site-packages/PyQt5/QtWidgets.abi3.so
#58 0x00007f668e4c2d97 in cfunction_call_varargs (func=, args=, kwargs=) at Objects/call.c:757
#59 0x00007f668e4c349b in _PyObject_MakeTpCall (callable=, args=, nargs=, keywords=0x0) at Objects/call.c:159
#60 0x00007f668e496533 in _PyObject_Vectorcall (kwnames=0x0, nargsf=, args=, callable=)
at ./Include/cpython/abstract.h:125
#61 _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:115
#62 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff90731d40, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#63 0x00007f668e49deca in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3469
#64 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'orangecanvas.application.application', '__doc__': '\n', '__package__': 'orangecanvas.application', '__loader__': , '__spec__': , origin='/home/denolf/dev/orange-canvas-core/orangecanvas/application/application.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/home/denolf/dev/orange-canvas-core/orangecanvas/application/__pycache__/application.cpython-38.pyc', _initializing=False) at remote 0x7f6656722100>, '__file__': '/home/denolf/dev/orange-canvas-core/orangecanvas/application/application.py', '__cached__': '/home/denolf/dev/orange-canvas-core/orangecanvas/application/__pycache__/application.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNotewort...(truncated), locals=locals@entry=0x0, args=, argcount=1, kwnames=0x0, kwargs=0x56353e1bb8d8, kwcount=0, kwstep=1, defs=0x0, defcount=0, kwdefs=0x0, closure=(,), name='exec', qualname='CanvasApplication.exec')
at Python/ceval.c:4298
#65 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=, stack=, nargsf=, kwnames=) at Objects/call.c:435
#66 0x00007f668e4c6c0a in _PyObject_Vectorcall (kwnames=0x0, nargsf=1, args=0x56353e1bb8d0, callable=) at ./Include/cpython/abstract.h:127
#67 method_vectorcall (method=, args=0x56353e1bb8d8, nargsf=, kwnames=0x0) at Objects/classobject.c:60
#68 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#69 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff90732090, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#70 0x00007f668e49deca in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3469
#71 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'orangecanvas.main', '__doc__': '\n', '__package__': 'orangecanvas', '__loader__': , '__spec__': , origin='/home/denolf/dev/orange-canvas-core/orangecanvas/main.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/home/denolf/dev/orange-canvas-core/orangecanvas/__pycache__/main.cpython-38.pyc', _initializing=False) at remote 0x7f6656794100>, '__file__': '/home/denolf/dev/orange-canvas-core/orangecanvas/main.py', '__cached__': '/home/denolf/dev/orange-canvas-core/orangecanvas/__pycache__/main.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNoteworthy: None is the `nil' object; Ellipsis represents `...' in slices.", '__package__': '', '__loader__': , '__spec__': , argcount=2, kwnames=0x0, kwargs=0x7f66569e38d8, kwcount=0, kwstep=1, defs=0x0, defcount=0, kwdefs=0x0, closure=0x0, name='run', qualname='Main.run') at Python/ceval.c:4298
#72 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=, stack=, nargsf=, kwnames=) at Objects/call.c:435
#73 0x00007f668e4c6c0a in _PyObject_Vectorcall (kwnames=0x0, nargsf=2, args=0x7f66569e38c8, callable=) at ./Include/cpython/abstract.h:127
#74 method_vectorcall (method=, args=0x7f66569e38d0, nargsf=, kwnames=0x0) at Objects/classobject.c:60
#75 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#76 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff907323e0, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#77 0x00007f668e49deca in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3469
#78 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'Orange.canvas.__main__', '__doc__': '\nOrange Canvas main entry point\n\n', '__package__': 'Orange.canvas', '__loader__': , '__spec__': , origin='/home/denolf/dev/orange3/Orange/canvas/__main__.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/home/denolf/dev/orange3/Orange/canvas/__pycache__/__main__.cpython-38.pyc', _initializing=False) at remote 0x7f665678c1f0>, '__file__': '/home/denolf/dev/orange3/Orange/canvas/__main__.py', '__cached__': '/home/denolf/dev/orange3/Orange/canvas/__pycache__/__main__.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNoteworthy: None is the `nil' object; Ellipsis represents `...' in slices.", '__package__': '', '__loader__': , '__spec__...(truncated), locals=locals@entry=0x0, args=, argcount=2, kwnames=0x0, kwargs=0x7f665673c848, kwcount=0, kwstep=1, defs=0x0, defcount=0, kwdefs=0x0, closure=(,), name='run', qualname='OMain.run')
at Python/ceval.c:4298
#79 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=, stack=, nargsf=, kwnames=) at Objects/call.c:435
#80 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#81 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff907326a0, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#82 0x00007f668e49a4d4 in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3486
#83 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': 'Orange.canvas.__main__', '__doc__': '\nOrange Canvas main entry point\n\n', '__package__': 'Orange.canvas', '__loader__': , '__spec__': , origin='/home/denolf/dev/orange3/Orange/canvas/__main__.py', loader_state=None, submodule_search_locations=None, _set_fileattr=True, _cached='/home/denolf/dev/orange3/Orange/canvas/__pycache__/__main__.cpython-38.pyc', _initializing=False) at remote 0x7f665678c1f0>, '__file__': '/home/denolf/dev/orange3/Orange/canvas/__main__.py', '__cached__': '/home/denolf/dev/orange3/Orange/canvas/__pycache__/__main__.cpython-38.pyc', '__builtins__': {'__name__': 'builtins', '__doc__': "Built-in functions, exceptions, and other objects.\n\nNoteworthy: None is the `nil' object; Ellipsis represents `...' in slices.", '__package__': '', '__loader__': , '__spec__...(truncated), locals=locals@entry=0x0, args=, argcount=1, kwnames=0x0, kwargs=0x56353e18ca78, kwcount=0, kwstep=1, defs=0x7f665678ce98, defcount=1, kwdefs=0x0, closure=0x0, name='main', qualname='main') at Python/ceval.c:4298
#84 0x00007f668e4c3234 in _PyFunction_Vectorcall (func=, stack=, nargsf=, kwnames=) at Objects/call.c:435
#85 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#86 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff90732968, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#87 0x00007f668e499a75 in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3500
#88 0x00007f668e49517b in function_code_fastcall (co=, args=, nargs=1, globals=) at Objects/call.c:283
#89 0x00007f668e4964ad in _PyObject_Vectorcall (kwnames=, nargsf=, args=, callable=) at ./Include/cpython/abstract.h:123
#90 call_function (tstate=tstate@entry=0x56353b103bb0, pp_stack=pp_stack@entry=0x7fff90732b48, oparg=, kwnames=kwnames@entry=0x0) at Python/ceval.c:4963
#91 0x00007f668e499a75 in _PyEval_EvalFrameDefault (f=, throwflag=) at Python/ceval.c:3500
#92 0x00007f668e5a97bb in _PyEval_EvalCodeWithName
(_co=_co@entry=, globals=globals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, locals=locals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, args=args@entry=0x0, argcount=argcount@entry=0, kwnames=kwnames@entry=0x0, kwargs=0x0, kwcount=0, kwstep=2, defs=0x0, defcount=0, kwdefs=0x0, closure=0x0, name=0x0, qualname=0x0)
at Python/ceval.c:4298
#93 0x00007f668e5a9b42 in PyEval_EvalCodeEx
(_co=_co@entry=, globals=globals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, locals=locals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, args=args@entry=0x0, argcount=argcount@entry=0, kws=kws@entry=0x0, kwcount=0, defs=0x0, defcount=0, kwdefs=0x0, closure=0x0) at Python/ceval.c:4327
#94 0x00007f668e5a9b6f in PyEval_EvalCode
(co=co@entry=, globals=globals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, locals=locals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': for more, q to quit, c to continue without paging--
unction at remote 0x7f6656741280>}) at Python/ceval.c:718
#95 0x00007f668e5e99fc in run_eval_code_obj
(locals={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, globals={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, co=0x7f668da03660)
at Python/pythonrun.c:1125
#96 run_mod
(mod=mod@entry=0x56353b1d53d0, filename=filename@entry='/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', globals=globals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, locals=locals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, flags=flags@entry=0x7fff90732e48, arena=arena@entry=0x7f668dac8550) at Python/pythonrun.c:1147
#97 0x00007f668e5eb376 in PyRun_FileExFlags
(fp=fp@entry=0x56353b102220, filename_str=filename_str@entry=0x7f668d9ac9f0 "/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas", start=start@entry=257, globals=globals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, locals=locals@entry={'__name__': '__main__', '__doc__': None, '__package__': None, '__loader__': , '__spec__': None, '__annotations__': {}, '__builtins__': , '__file__': '/users/denolf/virtualenvs/ewoks/ubuntu_20_04/py38/bin/ewoks-canvas', '__cached__': None, 're': , 'sys': , 'main': }, closeit=closeit@entry=1, flags=0x7fff90732e48)
at Python/pythonrun.c:1063
#98 0x00007f668e5eb4df in PyRun_SimpleFileExFlags (fp=fp@entry=0x56353b102220, filename=, closeit=closeit@entry=1, flags=flags@entry=0x7fff90732e48) at Python/pythonrun.c:428
#99 0x00007f668e5eba3c in PyRun_AnyFileExFlags (fp=fp@entry=0x56353b102220, filename=, closeit=closeit@entry=1, flags=flags@entry=0x7fff90732e48) at Python/pythonrun.c:86
#100 0x00007f668e609ad8 in pymain_run_file (cf=0x7fff90732e48, config=0x56353b102b80) at Modules/main.c:381
#101 pymain_run_python (exitcode=0x7fff90732e3c) at Modules/main.c:606
#102 Py_RunMain () at Modules/main.c:685
#103 0x00007f668e609f7a in pymain_main (args=0x7fff90732f40) at Modules/main.c:715
#104 Py_BytesMain (argc=, argv=) at Modules/main.c:739
#105 0x00007f668e234083 in __libc_start_main (main=0x56353a1d1060 , argc=3, argv=0x7fff907330a8, init=, fini=, rtld_fini=, stack_end=0x7fff90733098)
at ../csu/libc-start.c:308
#106 0x000056353a1d109e in _start ()
```

I can upload the workflow and the data (~1GB) somewhere if you want a way to reproduce the problem.