QGIS Crashes When Changing to Pie Chart Symbology (Diagrams

[charles483]

What is the bug or the crash?

When attempting to change the symbology of a layer to Pie Charts (Diagrams) in the latest version of QGIS, the application crashes unexpectedly. The crash occurs when selecting the Diagrams option under the Symbology tab, and specifically when trying to apply pie charts to display the relationship between population and area within polygons.

Steps to reproduce the issue

Open a layer with polygons (e.g., subcounty boundaries with attributes for population and area). Go to the Symbology tab in the Layer Properties window. Change the symbology type to Diagrams. Select Pie Chart as the diagram type. Configure the data fields for the pie chart (e.g., population and area). Apply the changes.

Versions

QGIS version 3.40.0-Bratislava QGIS code revision b56115d874

Libraries Qt version 5.15.13 Python version 3.12.7 GDAL/OGR version 3.9.3 PROJ version 9.5.0 EPSG Registry database version v11.016 (2024-08-31) GEOS version 3.13.0-CAPI-1.19.0 SQLite version 3.46.1 PDAL version 2.8.1 PostgreSQL client version unknown SpatiaLite version 5.1.0 QWT version 6.3.0 QScintilla2 version 2.14.1 OS version Windows 11 Version 2009

Active Python plugins geocatbridge 4.5.1 mmqgis 2024.11.8 QuickOSM 2.2.3 quick_map_services 0.19.34 SVG2ColoR 1.0 db_manager 0.1.20 grassprovider 2.12.99 MetaSearch 0.3.6 processing 2.12.99

Supported QGIS version

• [X] I'm running a supported QGIS version according to the roadmap.

New profile

• [X] I tried with a new QGIS profile

Additional context

No relevant error messages displayed, only an immediate crash.

[agiudiceandrea]

Already reported https://github.com/qgis/QGIS/issues/59324 and already fixed https://github.com/qgis/QGIS/pull/59340. The fix will be available in QGIS 3.40.1.