PyQt5 QtQuick

Tadinu

Hi,

After installing PyQt5.5.1 together with Qt5.5.1 on my Ubuntu 14.04 successfully, I ran my simple pyqt file using QtQuick and met this error:

libQt5Network.so.5: undefined symbol: _Z24qt_subtract_from_timeoutii

Anyone has run into this before?

Thanks.

Pyquick.py:

#!/usr/bin/env python3
import sys
from PyQt5.QtCore import QUrl
from PyQt5.QtWidgets import QApplication
from PyQt5.QtQuick import QQuickView

# Main Function
if __name__ == '__main__':
    # Create main app
    myApp = QApplication(sys.argv)
    # Create a label and set its properties
    appLabel = QQuickView()
    appLabel.setSource(QUrl('basic.qml'))

    # Show the Label
    appLabel.show()

    # Execute the Application and Exit
    myApp.exec_()
    sys.exit()

basic.qml:

import QtQuick 2.3

Rectangle {
    width: 300; height: 300
    color: "red"

    Text {
        id: helloText
        anchors.verticalCenter: parent.verticalCenter
        anchors.horizontalCenter: parent.horizontalCenter
        text: "Hello World!!!\n Traditional first app using PyQt5"
        color: "blue"
        font.family: "Helvetica"
        font.pointSize: 14
        horizontalAlignment: Text.AlignHCenter
    }

    Grid {
        id: colorPicker

        rows: 2; columns: 3; spacing: 3

        Rectangle { color: "white";}
        Rectangle { color: "green";}
        Rectangle { color: "blue"; }
        Rectangle { color: "yellow";}
        Rectangle { color: "steelblue";}
        Rectangle { color: "black";}
    }
}

Tadinu

The reason is i also installed python-Qt5, which is based on older Qt5 version.
With

find / -name libQt*

I could see some old qt lib residing in /usr/lib folder:

/usr/lib/i386-linux-gnu/libQt5Network.so
/usr/lib/i386-linux-gnu/libQt5Network.so.5
/usr/lib/i386-linux-gnu/libQt5Network.so.5.2
/usr/lib/i386-linux-gnu/libQt5Network.so.5.2.1

/home/tad/Qt5.5.1/gcc/lib/libQt5Network.so.5.5
/home/tad/Qt5.5.1/gcc/lib/libQt5Network.so
/home/tad/Qt5.5.1/gcc/lib/libQt5Network.so.5.5.1
/home/tad/Qt5.5.1/gcc/lib/libQt5Network.so.5

/home/tad/Qt5.5.1/Tools/QtCreator/lib/qtcreator/libQt5Network.so.5
/home/tad/Qt5.5.1/Tools/QtCreator/lib/qtcreator/libQt5Network.so.5.5.1
/home/tad/Qt5.5.1/Tools/QtCreator/lib/qtcreator/libQt5Network.so.5

The problem maybe inconsistent qt libs, so I remove all qt libs in /usr/lib and replace them with the ones in my home folder. It worked! However this is not recommended since some built-in Ubuntu components may use libQt* in /usr/lib folders. So, just remove python-qt5 and reinstall pyqt5 all over again!

By the way, for the error relating to Sip API version, we just have to run to remove all sip-related packages then reinstall sip again:

dpkg -l | grep sip

then

sudo apt-get purge python3-sip python3-sip-dev