# Contour segmentation fault

**URL:** https://discourse.paraview.org/t/contour-segmentation-fault/14402
**Category:** ParaView Support
**Created:** [April 15, 2024, 12:44pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402 "2024-04-15T12:44:10Z")
**Posts on this page:** 7
**Page:** 1

<div class="post-metadata">

### Author: ![Frankx9](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/f/3e96dc/32.png) [@Frankx9](https://discourse.paraview.org/u/Frankx9)
#### Post date: [April 15, 2024, 12:44pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/1 "2024-04-15T12:44:10Z")

</div>

Hello,

when I use the contour filter in Paraview I’m getting the following error:

```auto
Loguru caught a signal: SIGSEGV
Stack trace:
72 0x40802a /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/paraview-real() [0x40802a]
71 0x7fe85e217305 __libc_start_main + 133
70 0x7fe85e21724a /lib/x86_64-linux-gnu/libc.so.6(+0x2724a) [0x7fe85e21724a]
69 0x407c8a /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/paraview-real() [0x407c8a]
68 0x7fe85aa84120 QCoreApplication::exec() + 128
67 0x7fe85aa7b62a QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) + 298
66 0x7fe80945ee13 /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/plugins/platforms/../../lib/libQt5XcbQpa.so.5(+0x5ee13) [0x7fe80945ee13]
65 0x7fe85b2ee0db QWindowSystemInterface::sendWindowSystemEvents(QFlags<QEventLoop::ProcessEventsFlag>) + 187
64 0x7fe85b312b35 QGuiApplicationPrivate::processWindowSystemEvent(QWindowSystemInterfacePrivate::WindowSystemEvent*) + 261
63 0x7fe85b3118ad QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::MouseEvent*) + 1837
62 0x7fe85aa7cdd8 QCoreApplication::notifyInternal2(QObject*, QEvent*) + 280
61 0x7fe85d363260 QApplication::notify(QObject*, QEvent*) + 704
60 0x7fe85d35c18c QApplicationPrivate::notify_helper(QObject*, QEvent*) + 156
59 0x7fe85d3b68fb /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libQt5Widgets.so.5(+0x1b68fb) [0x7fe85d3b68fb]
58 0x7fe85d3b3d86 /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libQt5Widgets.so.5(+0x1b3d86) [0x7fe85d3b3d86]
57 0x7fe85d3627cc QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool, bool) + 460
56 0x7fe85aa7cdd8 QCoreApplication::notifyInternal2(QObject*, QEvent*) + 280
55 0x7fe85d363dc8 QApplication::notify(QObject*, QEvent*) + 3624
54 0x7fe85d35c18c QApplicationPrivate::notify_helper(QObject*, QEvent*) + 156
53 0x7fe85d399c28 QWidget::event(QEvent*) + 424
52 0x7fe85d43f945 QAbstractButton::mouseReleaseEvent(QMouseEvent*) + 213
51 0x7fe85d43f77a /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libQt5Widgets.so.5(+0x23f77a) [0x7fe85d43f77a]
50 0x7fe85d43e45a /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libQt5Widgets.so.5(+0x23e45a) [0x7fe85d43e45a]
49 0x7fe85d43e272 QAbstractButton::clicked(bool) + 50
48 0x7fe85aaab1ea QMetaObject::activate(QObject*, int, int, void**) + 1850
47 0x7fe85c9fd47f pqPropertiesPanel::apply() + 687
46 0x7fe85c8cf542 pqPropertiesPanel::applied(pqProxy*) + 50
45 0x7fe85aaab1ea QMetaObject::activate(QObject*, int, int, void**) + 1850
44 0x7fe85dce4551 pqApplyBehavior::applied(pqPropertiesPanel*, pqProxy*) + 193
43 0x7fe85dce56de pqApplyBehavior::showData(pqPipelineSource*, pqView*) + 414
42 0x7fe84b41b1c8 vtkSMParaViewPipelineControllerWithRendering::ShowInPreferredView(vtkSMSourceProxy*, int, vtkSMViewProxy*) + 168
41 0x7fe84b418f64 vtkSMParaViewPipelineControllerWithRendering::UpdatePipelineBeforeDisplay(vtkSMSourceProxy*, int, vtkSMViewProxy*) + 212
40 0x7fe8593fbd6c vtkSMSourceProxy::UpdatePipeline(double) + 140
39 0x7fe859379718 vtkSMOutputPort::UpdatePipelineInternal(double, bool) + 184
38 0x7fe8592c3c25 vtkPVSessionBase::ExecuteStream(unsigned int, vtkClientServerStream const&, bool) + 53
37 0x7fe8592c4bfb vtkPVSessionCore::ExecuteStream(unsigned int, vtkClientServerStream const&, bool) + 59
36 0x7fe8592c4dc2 vtkPVSessionCore::ExecuteStreamInternal(vtkClientServerStream const&, bool) + 242
35 0x7fe85761128d vtkClientServerInterpreter::ProcessStream(vtkClientServerStream const&) + 29
34 0x7fe857610fee vtkClientServerInterpreter::ProcessOneMessage(vtkClientServerStream const&, int) + 1294
33 0x7fe8576108bd vtkClientServerInterpreter::ProcessCommandInvoke(vtkClientServerStream const&, int) + 1229
32 0x7fe857610259 vtkClientServerInterpreter::CallCommandFunction(char const*, vtkObjectBase*, char const*, vtkClientServerStream const&, vtkClientServerStream&) + 345
31 0x7fe84c8a2bbb vtkSISourceProxyCommand(vtkClientServerInterpreter*, vtkObjectBase*, char const*, vtkClientServerStream const&, vtkClientServerStream&, void*) + 971
30 0x7fe8592fde44 vtkSISourceProxy::UpdatePipeline(int, double, bool) + 468
29 0x7fe852ec5d3a vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) + 282
28 0x7fe852e6ab36 vtkDemandDrivenPipeline::UpdateData(int) + 134
27 0x7fe852ec4979 vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 953
26 0x7fe852e6bb1e vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 222
25 0x7fe852e650f1 vtkCompositeDataPipeline::ForwardUpstream(vtkInformation*) + 337
24 0x7fe852ec4979 vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 953
23 0x7fe852e6bb76 vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 310
22 0x7fe852e66201 vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 113
21 0x7fe852e694f7 vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 55
20 0x7fe852e6f2ce vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) + 62
19 0x7fe83967e5bb vtkPVContourFilter::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 2043
18 0x7fe83967dd21 vtkPVContourFilter::ContourUsingSuperclass(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 673
17 0x7fe853432879 vtkContourFilter::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 4249
16 0x7fe852e5e1db vtkAlgorithm::UpdatePiece(int, int, int, int const*) + 139
15 0x7fe852e5f0aa vtkAlgorithm::Update(vtkInformation*) + 170
14 0x7fe852ec5d3a vtkStreamingDemandDrivenPipeline::Update(int, vtkInformationVector*) + 282
13 0x7fe852e6ab36 vtkDemandDrivenPipeline::UpdateData(int) + 134
12 0x7fe852ec4979 vtkStreamingDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 953
11 0x7fe852e6bb76 vtkDemandDrivenPipeline::ProcessRequest(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 310
10 0x7fe852e66201 vtkCompositeDataPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 113
9 0x7fe852e694f7 vtkDemandDrivenPipeline::ExecuteData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 55
8 0x7fe852e6f2ce vtkExecutive::CallAlgorithm(vtkInformation*, int, vtkInformationVector**, vtkInformationVector*) + 62
7 0x7fe853434eae vtkContourGrid::RequestData(vtkInformation*, vtkInformationVector**, vtkInformationVector*) + 494
6 0x7fe853434ae5 /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libvtkFiltersCore-pv5.10.so.1(+0x234ae5) [0x7fe853434ae5]
5 0x7fe853435d94 vtkContourHelper::Contour(vtkCell*, double, vtkDataArray*, long long) + 84
4 0x7fe8527c0ddb vtkHigherOrderHexahedron::Contour(double, vtkDataArray*, vtkIncrementalPointLocator*, vtkCellArray*, vtkCellArray*, vtkCellArray*, vtkPointData*, vtkPointData*, vtkCellData*, long long, vtkCellData*) + 219
3 0x7fe8527bab5e vtkHexahedron::Contour(double, vtkDataArray*, vtkIncrementalPointLocator*, vtkCellArray*, vtkCellArray*, vtkCellArray*, vtkPointData*, vtkPointData*, vtkCellData*, long long, vtkCellData*) + 990
2 0x7fe85277e0b0 vtkDataSetAttributes::CopyData(vtkDataSetAttributes*, long long, long long) + 96
1 0x7fe85016811a /scratch/user/Apps/ParaView-5.10.1-MPI-Linux-Python3.9-x86_64/bin/../lib/libvtkCommonCore-pv5.10.so.1(+0x56811a) [0x7fe85016811a]
0 0x7fe85e22c050 /lib/x86_64-linux-gnu/libc.so.6(+0x3c050) [0x7fe85e22c050]
( 93.614s) [paraview] :0 FATL| Signal: SIGSEGV

```

What is the reason? And how to solve it?

---

<div class="post-metadata">

### Author: ![ben.boeckel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.paraview.org/u/ben.boeckel)
#### Post date: [April 15, 2024, 2:49pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/2 "2024-04-15T14:49:28Z")

</div>

Can you share the data and pipeline setup that triggers this?

Cc: @mwestphal @cory.quammen

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<div class="post-metadata">

### Author: ![Frankx9](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/f/3e96dc/32.png) [@Frankx9](https://discourse.paraview.org/u/Frankx9)
#### Post date: [April 15, 2024, 3:37pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/3 "2024-04-15T15:37:28Z")

</div>

Unfortunately I cannot share the data at the moment. But do you have an idea on why this issue arise? It happens when I try to contour the QCriteron

Best

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<div class="post-metadata">

### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [April 15, 2024, 3:54pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/4 "2024-04-15T15:54:58Z")

</div>

> [@Frankx9](#):
>
> I cannot share the data at the moment

Then you may want to contact Kitware to set up a NDA: [https://www.kitware.eu/get-support/](https://www.kitware.eu/get-support/)

> But do you have an idea on why this issue arise?

Impossible to say without access to the data.

---

<div class="post-metadata">

### Author: ![Frankx9](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/f/3e96dc/32.png) [@Frankx9](https://discourse.paraview.org/u/Frankx9)
#### Post date: [April 15, 2024, 5:52pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/5 "2024-04-15T17:52:00Z")

</div>

I noticed a strange behaviour: if I run the script (to make the contour) multiple times sometimes it segfaults other works correctly (on average it works 1 time out of 5). The same happens in the GUI where the first time I hit apply returns an empty mesh while after that it works fine.

Any idea?

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<div class="post-metadata">

### Author: ![spyridon97](https://discourse.paraview.org/user_avatar/discourse.paraview.org/spyridon97/32/11569_2.png) [@spyridon97](https://discourse.paraview.org/u/spyridon97)
#### Post date: [April 15, 2024, 10:06pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/6 "2024-04-15T22:06:07Z")

</div>

Something tells me that you are trying to access memory that should not be accessed.

Using valgrind or address sanitizer will give you/us a better idea.

If the data were created by hand, then there is a possibility that you did not create the dataset correctly.

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<div class="post-metadata">

### Author: ![spyridon97](https://discourse.paraview.org/user_avatar/discourse.paraview.org/spyridon97/32/11569_2.png) [@spyridon97](https://discourse.paraview.org/u/spyridon97)
#### Post date: [April 15, 2024, 10:10pm UTC](https://discourse.paraview.org/t/contour-segmentation-fault/14402/7 "2024-04-15T22:10:44Z")

</div>

> [@Frankx9](#):
>
> `vtkHigherOrderHexahedron::Contour`

Also if you can not give the whole dataset, consider at least providing a subset of the dataset (using extract geometry or threshold) so that we can explore your issue, without revealing the content of your dataset.