Qt6 topics merged with General

libQt5XcbQpa.so.5: undefined symbol: _ZN22QWindowSystemInterface24setPlatformFiltersEventsEb

  • Hello,

    I have installed Qt5 on Ubuntu 20.04 using the online executable and then I have installed PyQt5 and matplotlib and I have the following error using python whenever I import matplotlib.pyplot (importing matplotlib does not generate any error)

    Do you know what is creating the issue with libQt5XcbQpa.so.5 ?


    Python 3.8.5 (default, Jul 28 2020, 12:59:40)
    Type 'copyright', 'credits' or 'license' for more information
    IPython 7.19.0 -- An enhanced Interactive Python. Type '?' for help.
    PyDev console: using IPython 7.19.0
    Python 3.8.5 (default, Jul 28 2020, 12:59:40)
    [GCC 9.3.0] on linux

    import matplotlib.pyplot as plt
    Backend Qt5Agg is interactive backend. Turning interactive mode on.
    /usr/bin/python3.8: symbol lookup error: /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5: undefined symbol: _ZN22QWindowSystemInterface24setPlatformFiltersEventsEb, version Qt_5_PRIVATE_API
    Process finished with exit code 127

  • Lifetime Qt Champion

    @LaGuiche55 said in libQt5XcbQpa.so.5: undefined symbol: _ZN22QWindowSystemInterface24setPlatformFiltersEventsEb:

    and then I have installed PyQt5 and matplotlib

    How exactly?

  • @jsulm Thanks for your answer
    I used a simple pip install for python 3.8
    pip3 install PyQt5
    pip3 install matplotlib

  • @LaGuiche55 Following your question, I have uninstalled and reinstalled those components and now it works .
    I have uninstalled Qt with ./MaintenanceTool
    pip uninstalled PyQt5
    pip uninstalled matplotlib
    sudo apt-get install qt5-default
    Qt install with online install executable
    pip install PyQt5
    pip install matplotlib


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