# Failures due to build order of Slicer CAT with superbuild remote modules

**URL:** https://discourse.slicer.org/t/failures-due-to-build-order-of-slicer-cat-with-superbuild-remote-modules/21841
**Category:** Support
**Created:** [February 7, 2022, 4:14pm UTC](https://discourse.slicer.org/t/failures-due-to-build-order-of-slicer-cat-with-superbuild-remote-modules/21841 "2022-02-07T16:14:23Z")
**Posts on this page:** 1
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<div class="post-metadata">

### Author: ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)
#### Post date: [February 8, 2022, 5:49pm UTC](https://discourse.slicer.org/t/failures-due-to-build-order-of-slicer-cat-with-superbuild-remote-modules/21841/8 "2022-02-08T17:49:30Z")

</div>

Following [2022.02.08 Weekly Meeting](https://discourse.slicer.org/t/2022-02-08-weekly-meeting/21843) discussion, we considered the following options:

1. Add a “virtual” project called `Slicer Dependencies` that would depend on all Slicer external project and ensure external projects from bundled SuperBuild extensions systematically depend on it.

2. Update `ExternalProjectDependency.cmake` to support customizing dependency of any external project.

We will move forward with approach (2)

### ExternalProject\_Add\_Dependencies

The good news is that the `ExternalProjectDependency` API already provide a function to do so:

[ExternalProject\_Add\_Dependencies](https://cmake-artichoke.readthedocs.io/en/latest/ExternalProjectDependency.html#function:ExternalProject_Add_Dependencies)

This means that custom application integrator should be able to address the integration of the issue specfic to `SlicerOpenCV` by adding:

```auto
ExternalProject_Add_Dependencies(ITKVideoBridgeOpenCV
  DEPENDS
    ITK
  )

```

### Path forward

This means that for now we have the flexibility of either updating extension or customizing the external project dependency graph when bundling extension in custom application.

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_[View the full topic](https://discourse.slicer.org/t/failures-due-to-build-order-of-slicer-cat-with-superbuild-remote-modules/21841)._