Crash when trying to open ElmerVTK in MSYS2/CLANG64 environment

[mmuetzel]

With a build from the release tarball of ElmerFEM 26.2 in the CLANG64 environment of MSYS2 (i.e., Windows/MinGW), trying to open the ElmerVTK postprocessor crashes ElmerGUI with the following output and backtrace from gdb:

warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: QDomDocument called with unopened QIODevice. This will not be supported in future Qt versions.
warning: ERROR: In vtkXMLParser.cxx, line 368
warning:
warning: vtkXMLDataParser (0x1cf1b1255e0): Error parsing XML in stream at line 1, column 1, byte index 1: not well-formed (invalid token)
warning:
warning:
warning: ERROR: In vtkXMLReader.cxx, line 577
warning:
warning: vtkXMLUnstructuredGridReader (0x1cf1b3dabc0): Error parsing input file.  ReadXMLInformation aborting.
warning:
warning:
warning: ERROR: In vtkExecutive.cxx, line 730
warning:
warning: vtkCompositeDataPipeline (0x1cf15c22090): Algorithm vtkXMLUnstructuredGridReader (0x1cf1b3dabc0) returned failure for request: vtkInformation (0x1cf1b2ba010)
warning:
warning:   Debug: Off
warning:
warning:   Modified Time: 6437
warning:
warning:   Reference Count: 1
warning:
warning:   Registered Events: (none)
warning:
warning:   Request: REQUEST_INFORMATION
warning:
warning:   ALGORITHM_AFTER_FORWARD: 1
warning:
warning:   FORWARD_DIRECTION: 0
warning:
warning:
warning:
warning:
warning: ERROR: In vtkXMLParser.cxx, line 368
warning:
warning: vtkXMLDataParser (0x1cf1b125d60): Error parsing XML in stream at line 1, column 1, byte index 1: not well-formed (invalid token)
warning:
warning:
warning: ERROR: In vtkXMLReader.cxx, line 577
warning:
warning: vtkXMLUnstructuredGridReader (0x1cf1b3dabc0): Error parsing input file.  ReadXMLInformation aborting.
warning:
warning:
warning: ERROR: In vtkExecutive.cxx, line 730
warning:
warning: vtkCompositeDataPipeline (0x1cf15c23b90): Algorithm vtkXMLUnstructuredGridReader (0x1cf1b3dabc0) returned failure for request: vtkInformation (0x1cf1b2b9350)
warning:
warning:   Debug: Off
warning:
warning:   Modified Time: 6565
warning:
warning:   Reference Count: 1
warning:
warning:   Registered Events: (none)
warning:
warning:   Request: REQUEST_INFORMATION
warning:
warning:   ALGORITHM_AFTER_FORWARD: 1
warning:
warning:   FORWARD_DIRECTION: 0
warning:
warning:
warning:
warning:

Thread 1 received signal SIGFPE, Arithmetic exception.
[Switching to Thread 27540.0x9f08]
0x00007ff7b64a0750 in VtkPost::ReadVtuFile(QString) ()
(gdb) bt
#0  0x00007ff7b64a0750 in VtkPost::ReadVtuFile(QString) ()
#1  0x00007ff7b649b3d3 in VtkPost::ReadPostFile(QString) ()
#2  0x00007ff7b632dc52 in VtkPost::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) ()
#3  0x00007ffd38df9e6a in void doActivate<false>(QObject*, int, void**) () from C:\msys64\clang64\bin\Qt6Core.dll
#4  0x00007ff7b632ae5a in ReadEpFile::readPostFileSignal(QString) ()
#5  0x00007ff7b64c8fbf in ReadEpFile::applyButtonClickedSlot() ()
#6  0x00007ff7b64c90dd in ReadEpFile::okButtonClickedSlot() ()
#7  0x00007ffd38df9e6a in void doActivate<false>(QObject*, int, void**) () from C:\msys64\clang64\bin\Qt6Core.dll
#8  0x00007ffd44a642fa in QAbstractButtonPrivate::emitClicked() () from C:\msys64\clang64\bin\Qt6Widgets.dll
#9  0x00007ffd44a63e81 in QAbstractButton::click() () from C:\msys64\clang64\bin\Qt6Widgets.dll
#10 0x00007ff7b64a4f5d in VtkPost::ReadSingleVtuFile(QString) ()
#11 0x00007ff7b639b4e2 in MainWindow::showVtkPostSlot() ()
#12 0x00007ffd38df9e6a in void doActivate<false>(QObject*, int, void**) () from C:\msys64\clang64\bin\Qt6Core.dll
#13 0x00007ffd443a564a in QAction::activate(QAction::ActionEvent) () from C:\msys64\clang64\bin\Qt6Gui.dll
#14 0x00007ffd44b24c35 in QMenuPrivate::activateCausedStack(QList<QPointer<QWidget> > const&, QAction*, QAction::ActionEvent, bool) ()
   from C:\msys64\clang64\bin\Qt6Widgets.dll
#15 0x00007ffd44b22020 in QMenuPrivate::activateAction(QAction*, QAction::ActionEvent, bool) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#16 0x00007ffd44b29e5f in QMenu::mouseReleaseEvent(QMouseEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#17 0x00007ffd44988b81 in QWidget::event(QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#18 0x00007ffd44b2a58a in QMenu::event(QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#19 0x00007ffd4492a22b in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#20 0x00007ffd4492c9d3 in QApplication::notify(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#21 0x00007ffd38d999db in QCoreApplication::sendSpontaneousEvent(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Core.dll
#22 0x00007ffd4492a8ca in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool, bool) ()
   from C:\msys64\clang64\bin\Qt6Widgets.dll
#23 0x00007ffd449a52a4 in QWidgetWindow::handleMouseEvent(QMouseEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#24 0x00007ffd449a40d8 in QWidgetWindow::event(QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#25 0x00007ffd4492a22b in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#26 0x00007ffd4492b2ff in QApplication::notify(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Widgets.dll
#27 0x00007ffd38d999db in QCoreApplication::sendSpontaneousEvent(QObject*, QEvent*) () from C:\msys64\clang64\bin\Qt6Core.dll
#28 0x00007ffd43efb88b in QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) ()
   from C:\msys64\clang64\bin\Qt6Gui.dll
#29 0x00007ffd43f71f0b in QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) ()
   from C:\msys64\clang64\bin\Qt6Gui.dll
#30 0x00007ffd38f74660 in QEventDispatcherWin32::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from C:\msys64\clang64\bin\Qt6Core.dll
#31 0x00007ffd442f6a99 in QWindowsGuiEventDispatcher::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from C:\msys64\clang64\bin\Qt6Gui.dll
#32 0x00007ffd38da4136 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from C:\msys64\clang64\bin\Qt6Core.dll
#33 0x00007ffd38d99532 in QCoreApplication::exec() () from C:\msys64\clang64\bin\Qt6Core.dll
#34 0x00007ff7b635cbfd in qMain(int, char**) ()
#35 0x00007ff7b64e9045 in main ()
(gdb)

The CLANG64 environment of MSYS2 is using a compiler toolchain and support libraries from the LLVM project.

The same operation doesn't crash when ElmerFEM is built for the UCRT64 environment of MSYS2. (That is using a compiler toolchain and support libraries from the GNU project.)

See also: msys2/MINGW-packages#29247