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  1. Qt for Python
  2. PYSIDE-1126

Segfault when QApplication exists before "import PySide2.QtCore"

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Details

    • Bug
    • Resolution: Done
    • Not Evaluated
    • None
    • 5.13.0
    • PySide
    • None
    • Debian Linux inside Docker with Qt 5.13.0 installed via the official installer. Tried PySide2 from pip and built from source.
    • Linux/X11

    Description

      When embedding Python/PySide2 into an existing Qt Application where the QtGuiApplication was created in C++ code before the "import PySide2" in python happens, the application crashes with a SIGSEGV.

      Minimal example:

      int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    Py_Initialize();
    PyRun_SimpleString("from PySide2.QtCore import Slot, Qt\n");

}

      Top of Stacktrace:

      #0  0x00007fd761ee2b90 in PyObject_GetAttrString () from /usr/lib/x86_64-linux-gnu/libpython3.7m.so.1.0
#1  0x00007fd751d67067 in NotifyModuleForQApp () from /usr/local/lib/python3.7/dist-packages/shiboken2/libshiboken2.cpython-37m-x86_64-linux-gnu.so.5.13
#2  0x00007fd751b1e30a in PyInit_QtCore () from /usr/local/lib/python3.7/dist-packages/PySide2/QtCore.cpython-37m-x86_64-linux-gnu.so
#3  0x00007fd761e36a93 in _PyImport_LoadDynamicModuleWithSpec () from /usr/lib/x86_64-linux-gnu/libpython3.7m.so.1.0

      The backtrace is huge with PyInit_QtCore and NotifiyModuleForQApp repeated over and over again. Might we an infinite loop that results in the crash.

      Attachments

        1. pyside1126_repro.diff
          1 kB
          Friedemann Kleint

        Issue Links

          relates to

          Bug - A problem which impairs or prevents the functions of the product. PYSIDE-1093 staticMetaObjects disappear when using QApplication.instance()

          • P1: Critical - Urgent and Important, will STOP the release if matched with set FixVersion field. This includes regressions from the last version that are not edge cases; Data loss; Build issues; All but the most unlikely crashes/lockups/hanging; Serious usability issues and embarrassing bugs & Bugs critical to a deliverable. This is the highest possible priority for requirements.
          • Closed
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              crmaurei Cristian Maureira-Fredes
              flauer F B
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              Dates

                Created:
                Updated:
                Resolved:

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