QGIS crash when using the python-lxml package (Windows) #58205

felixvons · 2024-07-22T15:59:46Z

What is the bug or the crash?

Hi,

I ran into an issue with the latest QGIS version when using lxml (e.g. from openpyxl) in a QGIS plugin or from the console.
I can force the crash from the Python console but not every time in my complex plugin setup.

Maybe the issue #55807 is related to this issue.

Python Stack Trace
Windows fatal exception: access violation

Current thread 0x00005718 (most recent call first):
  File "C:\Users/felix/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\test_qgis_plugin_qgis_crash_with_xml\tests\test_qgis.py", line 17 in test_lxml
    el = Element("test")
  File "C:\Users/felix/AppData/Roaming/QGIS/QGIS3\profiles\default/python/plugins\test_qgis_plugin_qgis_crash_with_xml\__init__.py", line 63 in run_lxml
    test_qgis.test_lxml()


Stack Trace


RtlpWaitOnCriticalSection :
RtlpEnterCriticalSectionContended :
RtlEnterCriticalSection :
xmlDictReference :
PyObject_Vectorcall :
PyObject_Vectorcall :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
Py_hashtable_compare_direct :
PyObject_Call :
PyObject_Call :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
QObject::qt_static_metacall :
QAbstractButton::clicked :
QAbstractButton::click :
QAbstractButton::mouseReleaseEvent :
PyInit_QtWidgets :
QWidget::event :
PyInit_QtWidgets :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QApplicationPrivate::sendMouseEvent :
QSizePolicy::QSizePolicy :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processMouseEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :




QGIS Info
QGIS Version: 3.34.9-Prizren
QGIS code revision: cbbc7bdf
Compiled against Qt: 5.15.13
Running against Qt: 5.15.13
Compiled against GDAL: 3.9.1
Running against GDAL: 3.9.1



System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.22631

Steps to reproduce the issue

You find a test plugin here: https://github.com/felixvons/test_qgis_plugin_qgis_crash_with_xml

Open an empty QGIS project
Drag & Drop a GeoPackage into the current project (or use the python code)
try to create an "lxml.etree.Element" in the python console
maybe retry the steps 2 and 3
QGIS crash

Versions

QGIS-Version	3.34.9-Prizren	QGIS-Codeversion	`cbbc7bd`
Qt-Version	5.15.13
Python-Version	3.12.4
GDAL-Version	3.9.1
PROJ-Version	9.4.0
EPSG-Registraturdatenbankversion	v11.004 (2024-02-24)
GEOS-Version	3.12.2-CAPI-1.18.2
SQLite-Version	3.45.1
PDAL-Version	2.6.3
PostgreSQL-Client-Version	16.2
SpatiaLite-Version	5.1.0
QWT-Version	6.2.0
QScintilla2-Version	2.14.1
BS-Version	Windows 11 Version 2009

Aktive Python-Erweiterungen
test_qgis_plugin_qgis_crash_with_xml	1.0
db_manager	0.1.20
grassprovider	2.12.99
MetaSearch	0.3.6
processing	2.12.99

QGIS-Version 3.34.9-Prizren QGIS-Codeversion [cbbc7bd](https://github.com/qgis/QGIS/commit/cbbc7bdf) Qt-Version 5.15.13 Python-Version 3.12.4 GDAL-Version 3.9.1 PROJ-Version 9.4.0 EPSG-Registraturdatenbankversion v11.004 (2024-02-24) GEOS-Version 3.12.2-CAPI-1.18.2 SQLite-Version 3.45.1 PDAL-Version 2.6.3 PostgreSQL-Client-Version 16.2 SpatiaLite-Version 5.1.0 QWT-Version 6.2.0 QScintilla2-Version 2.14.1 BS-Version Windows 11 Version 2009

Aktive Python-Erweiterungen
test_qgis_plugin_qgis_crash_with_xml
1.0
db_manager
0.1.20
grassprovider
2.12.99
MetaSearch
0.3.6
processing
2.12.99

Supported QGIS version

I'm running a supported QGIS version according to the roadmap.

New profile

I tried with a new QGIS profile

Additional context

The detailed reason for the crash is unknown to me.

I found two following solutions to fix the problem (for me):

rebuild lxml 5.2.1 from source on Windows
update lxml from 5.2.1 to 5.2.2

I created a small test plugin to force the crash with lxml/openpyxl: https://github.com/felixvons/test_qgis_plugin_qgis_crash_with_xml

The text was updated successfully, but these errors were encountered:

CharlesGag · 2024-07-31T15:25:16Z

Had a similar bug, updated lxml from 5.2.1 to 5.2.2 fixed it !

In my case, I was trying to load a workbook using openpyxl and it was crashing at that moment. Doing it in the QGIS Python console or outside qgis worked fine, but it crashed all the time when running it in my custom processing tool.

Thanks !

felixvons · 2024-08-26T06:20:32Z

Still persists in QGIS 3.34.10 LTR

Python Stack Trace

Windows fatal exception: access violation

Current thread 0x00003614 (most recent call first):
  File "C:\Users/XX/AppData/Roaming/QGIS/QGIS3\profiles\test/python/plugins\test_qgis_plugin_qgis_crash_with_xml\tests\test_qgis.py", line 17 in test_openpyxl_workbook
    el = Element("test")
  File "C:\Users/XX/AppData/Roaming/QGIS/QGIS3\profiles\test/python/plugins\test_qgis_plugin_qgis_crash_with_xml\__init__.py", line 56 in run
    test_qgis.test_openpyxl_workbook()

Stack Trace


RtlpWaitOnCriticalSection :
RtlpEnterCriticalSectionContended :
RtlEnterCriticalSection :
xmlDictReference :
PyObject_Vectorcall :
PyObject_Vectorcall :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
Py_hashtable_compare_direct :
PyObject_Call :
PyObject_Call :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
QObject::qt_static_metacall :
QAbstractButton::clicked :
QAbstractButton::click :
QAbstractButton::mouseReleaseEvent :
PyInit_QtWidgets :
QWidget::event :
PyInit_QtWidgets :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QApplicationPrivate::sendMouseEvent :
QSizePolicy::QSizePolicy :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processMouseEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :

QGIS Info
QGIS Version: 3.34.10-Prizren
QGIS code revision: 113de9e
Compiled against Qt: 5.15.13
Running against Qt: 5.15.13
Compiled against GDAL: 3.9.2
Running against GDAL: 3.9.2

System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.22631

jakosek · 2024-09-11T22:14:02Z

same for me, random crashes with python-docx (internally use lxml), upgrade to lxml-5.3.0 solved crash

Djedouas · 2024-12-02T11:07:07Z

Hi @jef-n , apparently python3-lxml has to be updated in Windows packaging

felixvons · 2025-01-27T11:13:18Z

Hi,

still valid in newest LTR 3.34.15

Report Details

Python Stack Trace

Windows fatal exception: access violation

Current thread 0x00003d04 (most recent call first):
  File "C:\Users/XXX/AppData/Roaming/QGIS/QGIS3\profiles\test/python/plugins\test_qgis_plugin_qgis_crash_with_xml\tests\test_qgis.py", line 17 in test_openpyxl_workbook
    el = Element("test")
  File "C:\Users/XXX/AppData/Roaming/QGIS/QGIS3\profiles\test/python/plugins\test_qgis_plugin_qgis_crash_with_xml\__init__.py", line 56 in run
    test_qgis.test_openpyxl_workbook()

Stack Trace


RtlpWaitOnCriticalSection :
RtlpEnterCriticalSectionContended :
RtlEnterCriticalSection :
xmlDictReference :
PyObject_Vectorcall :
PyObject_Vectorcall :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
PyArg_CheckPositional :
PyObject_Call :
PyObject_Call :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
PyInit_QtCore :
QObject::qt_static_metacall :
QAbstractButton::clicked :
QAbstractButton::click :
QAbstractButton::mouseReleaseEvent :
PyInit_QtWidgets :
QWidget::event :
PyInit_QtWidgets :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QApplicationPrivate::sendMouseEvent :
QSizePolicy::QSizePolicy :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processMouseEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :

QGIS Info
QGIS Version: 3.34.15-Prizren
QGIS code revision: 386f258
Compiled against Qt: 5.15.13
Running against Qt: 5.15.13
Compiled against GDAL: 3.10.1
Running against GDAL: 3.10.1

System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.22631

Djedouas · 2025-01-31T12:16:39Z

Hi @jef-n , the python3-lxml package version currently in OSGeo4W build crashes QGIS, how could we update the package version?

Previous comment:

upgrade to lxml-5.3.0 solved crash

Thanks

agiudiceandrea · 2025-01-31T18:07:16Z

@Djedouas, the python3-lxml package version 5.3.0 is now available in the OSGeo4W repository.

Djedouas · 2025-02-04T08:49:48Z

@felixvons hi, could you check the version of lxml please?

In QGIS python console:

import lxml
print(lxml.__version__)

and provide a sample python code that when run in the QGIS python console crashes?

Thanks

agiudiceandrea · 2025-02-04T10:43:46Z

@Djedouas, @jef-n, it seems to me QGIS 3.40.3 on Windows 10 from OSGeo4W crashes even using lxml 5.3.0 (python3-lxml 5.3.0-1). I guess the issue is not related to the QGIS source code, but is it due to the lxml Python module shipped by OSGeo4W, so the issue should be reported to https://trac.osgeo.org/osgeo4w/.

As indicated in the description, in order to make QGIS crash just:

import a GeoPackage layer in a new empty project
execute the following code in the Python console:

from lxml import etree
root = etree.Element("root")

Python Stack Trace
Windows fatal exception: access violation

Current thread 0x00003bd4 (most recent call first):
  File "C:\OS5C2A~1\apps\Python312\Lib\code.py", line 90 in runcode
    exec(code, self.locals)
  File "C:\OS5C2A~1\apps\Python312\Lib\code.py", line 74 in runsource
    self.runcode(code)
  File "C:\OS5C2A~1/apps/qgis/./python\console\console_sci.py", line 261 in runsource
    return super().runsource(source, filename, symbol)
  File "C:\OS5C2A~1/apps/qgis/./python\console\console_sci.py", line 237 in execCommandImpl
    res = self.runsource(src)
  File "C:\OS5C2A~1/apps/qgis/./python\console\console_sci.py", line 380 in keyPressEvent
    super().keyPressEvent(e)


Stack Trace


RtlpWaitOnCriticalSection :
RtlpEnterCriticalSectionContended :
RtlEnterCriticalSection :
xmlDictReference :
PyObject_Vectorcall :
PyObject_Vectorcall :
PyEval_EvalFrameDefault :
PyDict_MergeFromSeq2 :
PyEval_EvalCode :
PyList_SetSlice :
PyList_SetSlice :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
PyArg_CheckPositional :
PyObject_Call :
PyObject_Call :
PyInit_sip :
PyInit_sip :
PyInit__gui :
QgsCodeEditor::runCommand :
QgsCodeEditor::keyPressEvent :
QgsCodeEditorPython::keyPressEvent :
PyInit__gui :
PyLong_FromString :
PyObject_Vectorcall :
PyObject_Vectorcall :
PyEval_EvalFrameDefault :
PyFunction_Vectorcall :
PyArg_CheckPositional :
PyObject_Call :
PyObject_Call :
PyInit_sip :
PyInit_sip :
PyInit__gui :
QWidget::event :
QFrame::event :
QAbstractScrollArea::event :
PyInit__gui :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QSizePolicy::QSizePolicy :
QApplicationPrivate::notify_helper :
QApplication::notify :
QgsApplication::notify :
QCoreApplication::notifyInternal2 :
QGuiApplicationPrivate::processKeyEvent :
QWindowSystemInterface::sendWindowSystemEvents :
QEventDispatcherWin32::processEvents :
qt_plugin_query_metadata :
QEventLoop::exec :
QCoreApplication::exec :
main :
BaseThreadInitThunk :
RtlUserThreadStart :




QGIS Info
QGIS Version: 3.40.3-Bratislava
QGIS code revision: 2a274ab7
Compiled against Qt: 5.15.13
Running against Qt: 5.15.13
Compiled against GDAL: 3.10.1
Running against GDAL: 3.10.1



System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 10.0.18362

felixvons · 2025-02-04T10:54:14Z

Hi,
thank you for other checks and tests.

For me and my usecase it is not possible to use the osgeo4w installer. I am using the shipped MSI installer and in the MSI installer the version 5.2.1 is shipped.

Djedouas · 2025-02-06T08:42:00Z

Reproduced on Windows (lxml 5.2.1), not on Linux (lxml 5.3.0).

@felixvons as @agiudiceandrea I think that in this case, the issue is not related to the QGIS source code, but is due to the lxml Python module shipped by OSGeo4W.

Could you report it to https://trac.osgeo.org/osgeo4w/ please?

Thanks

felixvons added the Bug Either a bug report, or a bug fix. Let's hope for the latter! label Jul 22, 2024

agiudiceandrea added Packaging Windows Related to Windows operating system labels Jul 22, 2024

matjash mentioned this issue Dec 5, 2024

QGIS crash on save to xlsx, Windows fatal exception: access violation #55807

Closed

2 tasks

Djedouas added the Feedback Waiting on the submitter for answers label Feb 4, 2025

agiudiceandrea added the Downstream Downstream packaging issues etc. label Feb 4, 2025

Djedouas removed the Feedback Waiting on the submitter for answers label Feb 4, 2025

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QGIS crash when using the python-lxml package (Windows) #58205

QGIS crash when using the python-lxml package (Windows) #58205

felixvons commented Jul 22, 2024

CharlesGag commented Jul 31, 2024 •

edited

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felixvons commented Aug 26, 2024

jakosek commented Sep 11, 2024

Djedouas commented Dec 2, 2024 •

edited

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felixvons commented Jan 27, 2025 •

edited

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Djedouas commented Jan 31, 2025

agiudiceandrea commented Jan 31, 2025 •

edited

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Djedouas commented Feb 4, 2025

agiudiceandrea commented Feb 4, 2025 •

edited

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felixvons commented Feb 4, 2025

Djedouas commented Feb 6, 2025

QGIS crash when using the python-lxml package (Windows) #58205

QGIS crash when using the python-lxml package (Windows) #58205

Comments

felixvons commented Jul 22, 2024

What is the bug or the crash?

Steps to reproduce the issue

Versions

Supported QGIS version

New profile

Additional context

CharlesGag commented Jul 31, 2024 • edited Loading

felixvons commented Aug 26, 2024

jakosek commented Sep 11, 2024

Djedouas commented Dec 2, 2024 • edited Loading

felixvons commented Jan 27, 2025 • edited Loading

Report Details

Djedouas commented Jan 31, 2025

agiudiceandrea commented Jan 31, 2025 • edited Loading

Djedouas commented Feb 4, 2025

agiudiceandrea commented Feb 4, 2025 • edited Loading

felixvons commented Feb 4, 2025

Djedouas commented Feb 6, 2025

CharlesGag commented Jul 31, 2024 •

edited

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Djedouas commented Dec 2, 2024 •

edited

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felixvons commented Jan 27, 2025 •

edited

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agiudiceandrea commented Jan 31, 2025 •

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agiudiceandrea commented Feb 4, 2025 •

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