PySide (shiboken) core dumps depending on script filename

JonB

My environment is Ubuntu 22.04, Python 3.10.6, Qt 5.15.3, all supplied with distro. I have added PyQt 5.15.6 and PySide2 5.15.2.1 and shiboken2 5.15.2.1. All is working well in general with Python/Qt/PyQt/PySide.

Today I created a script file named signal.py with the following content:

from PySide2 import QtCore

That's it! Just that one line (or anything else which reads in PySide2).

Then attempting to run python3 signal.py core dumps with following:

Problem importing shibokensupport:
cannot import name 'VoidPtr' from partially initialized module 'shiboken2' (most likely due to a circular import) (/home/jon/.local/lib/python3.10/site-packages/shiboken2/__init__.py)
Traceback (most recent call last):
  File "(builtin)", line 93, in ensure_shibokensupport
  File "(builtin)", line 133, in bootstrap
  File "/home/jon/.local/lib/python3.10/site-packages/shiboken2/files.dir/shibokensupport/signature/loader.py", line 222, in <module>
    move_into_pyside_package()
  File "/home/jon/.local/lib/python3.10/site-packages/shiboken2/files.dir/shibokensupport/signature/loader.py", line 196, in move_into_pyside_package
    import PySide2.support
  File "/home/jon/.local/lib/python3.10/site-packages/PySide2/support/__init__.py", line 40, in <module>
    from shiboken2 import VoidPtr
ImportError: cannot import name 'VoidPtr' from partially initialized module 'shiboken2' (most likely due to a circular import) (/home/jon/.local/lib/python3.10/site-packages/shiboken2/__init__.py)
sys.path:
  /home/jon/.local/lib/python3.10/site-packages/shiboken2/files.dir
  /home/jon/PySide2
  /usr/lib/python310.zip
  /usr/lib/python3.10
  /usr/lib/python3.10/lib-dynload
  /home/jon/.local/lib/python3.10/site-packages
  /usr/local/lib/python3.10/dist-packages
  /usr/lib/python3/dist-packages
Traceback (most recent call last):
  File "(builtin)", line 93, in ensure_shibokensupport
  File "(builtin)", line 133, in bootstrap
  File "/home/jon/.local/lib/python3.10/site-packages/shiboken2/files.dir/shibokensupport/signature/loader.py", line 222, in <module>
    move_into_pyside_package()
  File "/home/jon/.local/lib/python3.10/site-packages/shiboken2/files.dir/shibokensupport/signature/loader.py", line 196, in move_into_pyside_package
    import PySide2.support
  File "/home/jon/.local/lib/python3.10/site-packages/PySide2/support/__init__.py", line 40, in <module>
    from shiboken2 import VoidPtr
ImportError: cannot import name 'VoidPtr' from partially initialized module 'shiboken2' (most likely due to a circular import) (/home/jon/.local/lib/python3.10/site-packages/shiboken2/__init__.py)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "(builtin)", line 132, in bootstrap
  File "/usr/lib/python3.10/contextlib.py", line 153, in __exit__
    self.gen.throw(typ, value, traceback)
  File "(builtin)", line 102, in ensure_shibokensupport
SystemExit: -1

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "(builtin)", line 147, in bootstrap
UnboundLocalError: local variable 'loader' referenced before assignment
Fatal Python error: could not initialize part 2
Python runtime state: initialized

Current thread 0x00007fad29c10000 (most recent call first):
  File "/usr/lib/python3.10/subprocess.py", line 450 in CompletedProcess
  File "/usr/lib/python3.10/subprocess.py", line 424 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "/usr/lib/python3.10/platform.py", line 119 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "/usr/lib/python3/dist-packages/numpy/core/_add_newdocs_scalars.py", line 9 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1078 in _handle_fromlist
  File "/usr/lib/python3/dist-packages/numpy/core/__init__.py", line 99 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1078 in _handle_fromlist
  File "/usr/lib/python3/dist-packages/numpy/__init__.py", line 150 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 992 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 992 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 1176 in create_module
  File "<frozen importlib._bootstrap>", line 571 in module_from_spec
  File "<frozen importlib._bootstrap>", line 674 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "/home/jon/.local/lib/python3.10/site-packages/shiboken2/__init__.py", line 27 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "/home/jon/.local/lib/python3.10/site-packages/PySide2/__init__.py", line 58 in _setupQtDirectories
  File "/home/jon/.local/lib/python3.10/site-packages/PySide2/__init__.py", line 107 in <module>
  File "<frozen importlib._bootstrap>", line 241 in _call_with_frames_removed
  File "<frozen importlib._bootstrap_external>", line 883 in exec_module
  File "<frozen importlib._bootstrap>", line 688 in _load_unlocked
  File "<frozen importlib._bootstrap>", line 1006 in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 1027 in _find_and_load
  File "/home/jon/PySide2/signal.py", line 1 in <module>

Extension modules: numpy.core._multiarray_umath, numpy.core._multiarray_tests, xxsubtype, PySide2.QtCore, apt_pkg (total: 5)
Aborted (core dumped)

Yep, that's what I get :(

If I change from PySide2 import QtCore to from PyQt5 import QtCore all is well. So it's a PySide (or shiboken) issue.

Sat for a while completely befuddled. Eventually totally on a hunch I renamed script file from signal.py to ABCsignal.py. Guess what, sure enough it works fine under PySide2....

So that means something about PySide2 cannot cope correctly with certain filenames, doubtless which happen to be the same as supplied one. I note that my Python 3.10 comes with a /usr/lib/python3.10/signal.py, which I would guess is the issue. Goodness knows how many other filenames could potentially have similar behaviour.

Sorry, but this is terrible, especially since PyQt5 has no problem!

I cannot test with Qt6/PySide6. Would somebody be so kind as to test:

This one-line program with PySide2, perhaps under Linux. Do you get the same core dump?
Test with PySide6. Does that work, or is it just as bad?

From this I will know whether/what to report as a PySide bug.
Thank you.

SGaist

Hi,

It did work with PySide6 and PyQt6 on macOS.

I currently don't have PySide2 at hand but will try when I have.

JonB

@SGaist
Thank you, please try with PySide2 if you have the time.

I keep forgetting you are MacOS, for some reason. I am told by Mac users that "everything just works, all the time", so maybe this is hardly surprising ;-)

SGaist

@JonB It's more a question of architecture. PySide2 is, to the best of my knowledge, not available pre-built for Apple's M series of processor.

As for everything always working, well, that's not absolutely completely true ;-)