pyqgisdebug_ubuntu.md

Debugging QGIS 3.x python plugins on Ubuntu 22.04 using VS Code

My setup uses Ubuntu 22.04 running on Windows WSL2, which suppots executing GUI applications.

Setting up VS Code

NOTE: I'm using VS Code Python Debugger extension version v2024.12.0 (ms-python.debugpy), which uses debugpy.

QGIS

In my setup I'm running QGIS built from source, following the official instructions. My build is under /home/giohappy/dev/qgis/QGIS/build.

Configure VS Code

I start VS Code from the plugin folder. In my case I'm testing QGISGeoNodePlugin that I have cloned from Github.

settings.json

{
    "terminal.integrated.env.linux": {
        "PYTHONPATH": "/home/giohappy/dev/qgis/QGIS/build/output/python",
    },
    "python.analysis.include": [
        "/home/giohappy/dev/qgis/QGIS/build/output/python"
    ],
    "python.analysis.extraPaths": [
        "/home/giohappy/dev/qgis/QGIS/build/output/python"
    ]
}  

NOTE: PyQT5 is installed on the machine, since they have been installed from apt to build QGIS form source, so I don't need to add it to the settings.

Launch.json

Remote debugger configuration for debugpy

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Python: Remote Attach",
            "type": "debugpy",
            "request": "attach",
            "connect": {
                "port": 5678,
            }
        }
    ]
}

Build the plugin

From the plugin folder (e.g. /home/giohappy/dev/qgis/QGISGeoNodePlugin) run:

• `python -m venv venv && ./venv/bin/activate && pip install poetry
• pip install . to install the build deps
• python pluginadmin.py build

The plugin will be created under the build folder.

Then we symlink the plugin to the QGIS plugins folder:

• ln -s /home/giohappy/dev/qgis/QGISGeoNodePlugin/build/qgis_geonode/ /home/giohappy/.local/share/QGIS/QGIS3/profiles/default/python/plugins/qgis_geonode

Running the debugger inside the plugin

The DebuVS QGIS Plugin needs debugpy. I have installed it globallty with pip3 install debugy.

Then: )

• Run QGIS
• Enable the plugin from the Plugins Installer, if not yet enabled
• Under the plugins menu click "Enable Debuf for Visual Studio"
• If all goes fine the message bar should print "INFO DebugVS : Remote Debug for Visual Studio is running("request": "enable_attach", "Port": 5678, "host": "localhost")"

Now you should be ready to debug!

Debugging

In VS Code

• start debugging using the Python: Remote Attach configuration defined above.
• Place the breakpoints inside the code inside the build folder.

Now you should be able to step debug in VS Code