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qtqmlqt5qt-creatorpyside2

How to profile PySide2 + QML in QtCreator?

I have a PySide2 application, which uses QML to display the user interface. The application works from the command line. I can also launch it as well as debug it in QtCreator. However, when I try to run QmlProfiler, I see the following error:

:-1: error: /home/username/code/project/venv/bin/python: Error while finding module specification for 'ljsdebugger=file:/tmp/QtCreator-kVUFuF/qtcreator-freesocket.XgLEKq,block,services:CanvasFrameRate,EngineControl,DebugMessages,DebugTranslation' (ModuleNotFoundError: No module named 'ljsdebugger=file:/tmp/QtCreator-kVUFuF/qtcreator-freesocket')

I checked project's kit settings and it is using all the defaults. I could not find any relevant articles/discussions with this error message on the web. How to resolve this issue?

Solution

  • Solving this involves two steps:

    1. Make the application debugging enabled

    Add the line before QApplication is instantated:

    from PySide2.QtQml import QQmlDebuggingEnabler

debug = QQmlDebuggingEnabler()
    1. Connect it to the QML Profiler

    run the application with the command line parameter: -qmljsdebugger=port:10002,block with the port of your choice. Then go to Analyze>QML Profiler (Attach to Waiting Application) and choose the port you started the program with: enter image description here

    This successfully connected the program to the QML Profiler.