# OpenCV extension build fails since June ITK upgrade

**URL:** <https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158>\
**Category:** Development\
**Tags:** opencv, extensions\
**Created:** [September 2, 2024, 2:33pm UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158 "2024-09-02T14:33:49Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [September 2, 2024, 2:33pm UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/1 "2024-09-02T14:33:49Z")

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Hi all,

The OpenCV extension build fails on all three platform since June 4, most probably due to the ITK upgrade: [ENH: Update ITK to 5.4.0 · Slicer/Slicer@acf3dd4 · GitHub](https://github.com/Slicer/Slicer/commit/acf3dd47940665869765584564b38439f73ff1d5)

This is the first failure on the dashboard:  
[https://slicer.cdash.org/index.php?project=SlicerPreview&date=2024-06-04&filtercount=1&showfilters=1&field1=label&compare1=63&value1=opencv](https://slicer.cdash.org/index.php?project=SlicerPreview&date=2024-06-04&filtercount=1&showfilters=1&field1=label&compare1=63&value1=opencv)

The relevant error seems to be:

```auto
"ITK_FIND_REQUIRED_ITKVideoBridgeOpenCV" "OR" "M" "IN_LIST" "ITK_MODULES_ENABLED"

  Unknown arguments specified
Call Stack (most recent call first):
  SlicerOpenCV/Logic/CMakeLists.txt:6 (find_package)

```

Does anyone know off the bat what this unknown argument is and how to fix it? Thanks a lot!

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [September 6, 2024, 9:11am UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/2 "2024-09-06T09:11:27Z")

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@jcfr @jamesobutler @adamrankin Have you seen this? The extension is down for three months. If it is not needed anymore, that would also be useful to know. Thanks!

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**Author:** ![adamrankin](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/adamrankin/32/155_2.png) [@adamrankin](https://discourse.slicer.org/u/adamrankin)\
**Post date:** [September 6, 2024, 11:05am UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/3 "2024-09-06T11:05:54Z")

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Yes, probably time to kill it. If someone needs it, it can be brought back

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**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [September 6, 2024, 11:07am UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/4 "2024-09-06T11:07:25Z")

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I need it 🙂 Or importing OpenCV is now trivial via pip?

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**Author:** ![adamrankin](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/adamrankin/32/155_2.png) [@adamrankin](https://discourse.slicer.org/u/adamrankin)\
**Post date:** [September 6, 2024, 11:46am UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/5 "2024-09-06T11:46:08Z")

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Yes, extension only has value for downstream c++ extensions

Python is solved by pip

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<div class="post-metadata">

**Author:** ![cpinter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/cpinter/32/7995_2.png) [@cpinter](https://discourse.slicer.org/u/cpinter)\
**Post date:** [September 6, 2024, 11:59am UTC](https://discourse.slicer.org/t/opencv-extension-build-fails-since-june-itk-upgrade/38158/6 "2024-09-06T11:59:58Z")

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Thanks Adam, you just saved me some time. I assumed the extension it was still needed for some reason.