# Slicer Extension Manager build error: Missing Photogrammetry.json on CDash
**URL:** https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707
**Category:** Support
**Created:** [February 14, 2025, 6:43pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707 "2025-02-14T18:43:01Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@oothomas](https://discourse.slicer.org/u/oothomas)
#### Post date: [February 14, 2025, 6:43pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707/1 "2025-02-14T18:43:01Z")
Hello everyone,
I’m having trouble with my **SlicerPhotogrammetry** extension on the **Slicer Preview** dashboard. This is not a personal/local build; it’s built on the official dashboard (CDash). Despite the build itself completing successfully, packaging fails with this error:
```auto
CMake Error at /work/Preview/Slicer-0/Extensions/CMake/SlicerFunctionExtractExtensionDescription.cmake:135 (message):
error: EXTENSION_FILE CMake variable points to a nonexistent file or directory:
/.../SlicerPhotogrammetry-build/./Photogrammetry.json
Call Stack (most recent call first):
/work/Preview/Slicer-0/Extensions/CMake/SlicerExtensionPackageAndUploadTarget.cmake:206 (slicerFunctionExtractExtensionDescriptionFromJson)
```
Is Photogrammetry.json being references because of the module name or the extension index .json file having the wrong name?
The extension includes two scripted modules (Photogrammetry and ClusterPhotos) and a standard CMakeLists.txt that sets EXTENSION\_NAME, EXTENSION\_DESCRIPTION, etc. I do see a .s4ext file generated, but I don’t see a corresponding .json file in the build directory. For some reason, the build system references Photogrammetry.json yet never seems to generate it.
Has anyone encountered a similar issue or know how to ensure the .json file is properly created and recognized? Any guidance on what might be missing in my extension’s configuration to keep CDash from throwing this error would be greatly appreciated.
Thanks so much!
---
### Author:  [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)
#### Post date: [February 15, 2025, 2:29pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707/2 "2025-02-15T14:29:43Z")
@oothomas Check the extensions manager tomorrow following the change I pushed at:
>
---
### Author:  [@muratmaga](https://discourse.slicer.org/u/muratmaga)
#### Post date: [February 16, 2025, 7:07pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707/3 "2025-02-16T19:07:12Z")
@jamesobutler thanks for the fixes. Looks like it is built for preview but is not listed for Stable? Any idea why that might be the case?
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### Author:  [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)
#### Post date: [February 16, 2025, 7:37pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707/4 "2025-02-16T19:37:42Z")
The Photogrammetry was only submitted to the `main` branch of the extensions index making it available for Slicer Preview builds.
> **[GitHub - Slicer/ExtensionsIndex: Slicer extensions index](https://github.com/Slicer/ExtensionsIndex/tree/main)**
>
> main
A PR has to be submitted to the `5.8` branch to make it available for the Slicer 5.8.x stable releases.
> **[GitHub - Slicer/ExtensionsIndex at 5.8](https://github.com/Slicer/ExtensionsIndex/tree/5.8)**
>
> 5.8
---
### Author:  [@muratmaga](https://discourse.slicer.org/u/muratmaga)
#### Post date: [February 16, 2025, 8:03pm UTC](https://discourse.slicer.org/t/slicer-extension-manager-build-error-missing-photogrammetry-json-on-cdash/41707/5 "2025-02-16T20:03:40Z")
Got it thanks for the pointer.