qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in the virtualenv

[Black Cat]

Hi,

I'm trying to run a Python application in the virtualenv, but, when I try to start I receive this error:

*qt.qpa.plugin: Could not load the Qt platform plugin "xcb"*

What is supposed to do for resolve this error?

INFO

OS: Kali Linux 2020.4
PyQt5: 5.15.2

DEBUG:

QFactoryLoader::QFactoryLoader() checking directory path "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqeglfs.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqeglfs.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "eglfs"
        ]
    },
    "archreq": 0,
    "className": "QEglFSIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqlinuxfb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "linuxfb"
        ]
    },
    "archreq": 0,
    "className": "QLinuxFbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqminimal.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqminimal.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimal"
        ]
    },
    "archreq": 0,
    "className": "QMinimalIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqminimalegl.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqminimalegl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "minimalegl"
        ]
    },
    "archreq": 0,
    "className": "QMinimalEglIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqoffscreen.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqoffscreen.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "offscreen"
        ]
    },
    "archreq": 0,
    "className": "QOffscreenIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqvnc.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqvnc.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "vnc"
        ]
    },
    "archreq": 0,
    "className": "QVncIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("vnc")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-egl.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-egl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-egl"
        ]
    },
    "archreq": 0,
    "className": "QWaylandEglPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-egl")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-generic.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-generic.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland"
        ]
    },
    "archreq": 0,
    "className": "QWaylandIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-xcomposite-egl.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-xcomposite-egl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-xcomposite-egl"
        ]
    },
    "archreq": 0,
    "className": "QWaylandXCompositeEglPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-xcomposite-egl")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-xcomposite-glx.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwayland-xcomposite-glx.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "wayland-xcomposite-glx"
        ]
    },
    "archreq": 0,
    "className": "QWaylandXCompositeGlxPlatformIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("wayland-xcomposite-glx")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwebgl.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqwebgl.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "webgl"
        ]
    },
    "archreq": 0,
    "className": "QWebGLIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("webgl")
QFactoryLoader::QFactoryLoader() looking at "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so"
Found metadata in lib /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so, metadata=
{
    "IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.3",
    "MetaData": {
        "Keys": [
            "xcb"
        ]
    },
    "archreq": 0,
    "className": "QXcbIntegrationPlugin",
    "debug": false,
    "version": 331520
}


Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/usr/bin/platforms" ...
Cannot load library /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so: (libxcb-util.so.1: cannot open shared object file: No such file or directory)
QLibraryPrivate::loadPlugin failed on "/home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so" : "Cannot load library /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so: (libxcb-util.so.1: cannot open shared object file: No such file or directory)"
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, webgl, xcb.

zsh: abort      python3 main.py
                                  

[JonB]

@Black-Cat
Try a

ldd /home/root/venv1/lib/python3.8/site-packages/PyQt5/Qt/plugins/platforms/libqxcb.so

It shows libxcb-util.so.1 "not found"? Does it show anything else missing?

[eyllanesc]

@Black-Cat execute sudo apt-get install '^libxcb.*-dev'