Bug 519200 - darktable raw import fails
Summary: darktable raw import fails
Status: RESOLVED FIXED
Alias: None
Product: digikam
Classification: Applications
Component: Plugin-RawImport-Darktable (other bugs)
Version First Reported In: 9.0.0
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Digikam Developers
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2026-04-21 04:42 UTC by Wren Falcon
Modified: 2026-04-21 05:55 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed/Implemented In: 9.1.0
Sentry Crash Report:


Attachments
excerpt of logs from digikam 9.1.0 pre-release when trying to import from darktable (15.10 KB, text/plain)
2026-04-21 05:22 UTC, Wren Falcon
Details

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Description Wren Falcon 2026-04-21 04:42:34 UTC
SUMMARY
Something fails when trying to use darktable as a RAW (.CR3) editor through digiKam - while the image is opened in darktable, the edited image does not appear in the editing window of digiKam.

STEPS TO REPRODUCE
1. Ensure "Image Editor > RAW Behavior > Open raw files in the image editor" is set to "Always open ...: Raw Import using DarkTable"
2. Open a CR3 image in the editor (e.g. press F4 on it). The image then opens in darktable.
3. Make any desired edits (optional)
4. Close darktable.

OBSERVED RESULT
After a brief delay, a popup message is shown: "Error to import RAW image with DarkTable
Close this dialog to load RAW image with native import tool"
After closing the dialog, the unedited RAW appears in the editing window.

EXPECTED RESULT
The edited version of the image (made in darktable) should appear in the editing window.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 6.6.4
KDE Frameworks Version: 6.25.0
Qt Version: 6.11.0
Kernel Version: 6.19.10-hardened1-1-hardened (64-bit)
Graphics Platform: Wayland
Compositor: niri 25.11 (v25.11-189-ge9c182a1-modified)
darktable --version: darktable 5.4.1
"Raw Import using DarkTable": Version 9.0.0
SHA256 of `/usr/lib/qt6/plugins/digikam/rawimport/RawImport_DarkTable_Plugin.so`: 0769b4f50008e61f441b08f583e0b215fe70bfcd807d608cb307178f56a6d3de

ADDITIONAL INFORMATION
Originally came across the issue with a build of digiKam from git commit 756e33e37b. After discovering the issue, I switched from the locally-built version to digikam-9.0.0-1 from the Arch Linux repos.

Nothing particularly interesting or relevant showed up when running digikam from the terminal. How should I go about getting more logs/info?
Comment 1 caulier.gilles 2026-04-21 04:50:33 UTC
Get a debug trace following the instructions here : 

https://www.digikam.org/contribute/#freezes-and-other-run-time-issues

Another way is to test current 9.1.0 pre-release using the AppImage bundle to see if the problem is reproducible : 

https://files.kde.org/digikam/

Gilles Caulier
Comment 2 Wren Falcon 2026-04-21 05:22:44 UTC
Created attachment 191672 [details]
excerpt of logs from digikam 9.1.0 pre-release when trying to import from darktable
Comment 3 Wren Falcon 2026-04-21 05:25:02 UTC
(In reply to caulier.gilles from comment #1)
> Get a debug trace following the instructions here : 
> 
> https://www.digikam.org/contribute/#freezes-and-other-run-time-issues
> 
> Another way is to test current 9.1.0 pre-release using the AppImage bundle
> to see if the problem is reproducible : 
> 
> https://files.kde.org/digikam/
> 
> Gilles Caulier

Pre-release AppImage has same problem. See above logs. It appears (though it's not evident from the logs) that the temporary Darktable file is empty (0 bytes).
Comment 4 caulier.gilles 2026-04-21 05:31:34 UTC
From your log, the command line passed to DarkTable is this one :

DarkTable arguments: QList("--library", ":memory:", "--luacmd", "dofile('/tmp/LuaScript-TZBWnS-295978a0')", "--conf", "plugins/lighttable/export/icctype=-1", "--conf", "lua/export_on_exit/export_filename=/tmp/Darktable-QCXSQE-f6658561", "/run/media/wren/Crucial X9/Canon/IMPORT_5/2026-04-20/IMG_9310.CR3")

and it return OK but generated output file is empty or broken:

unknown: DarkTable :: return code: 0 :: Exit status: QProcess::NormalExit
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
unknown: Failed to read header of file  "/tmp/Darktable-QCXSQE-f6658561"
Digikam::DImg::load: "/tmp/Darktable-QCXSQE-f6658561" : Unknown image format !!!

Q : can you share this CR3 file through a cloud storage: 

/run/media/wren/Crucial X9/Canon/IMPORT_5/2026-04-20/IMG_9310.CR3
Comment 5 Wren Falcon 2026-04-21 05:35:28 UTC
Actually... presumably the issue is with the darktable build. From digikam logs:
> unknown: DarkTable arguments: QList("--library", ":memory:", "--luacmd", "dofile('/tmp/LuaScript-TZBWnS-295978a0')", "--conf", "plugins/lighttable/export/icctype=-1", "--conf", "lua/export_on_exit/export_filename=/tmp/Darktable-sEGYOv-0cdfce78", "/run/media/wren/Crucial X9/Canon/IMPORT_5/2026-04-20/IMG_9310.CR3")

And darktable --version (indicates no Lua):
> darktable 5.4.1
> Copyright (C) 2012-2026 Johannes Hanika and other contributors.
> 
> Compile options:
>   Bit depth              -> 64 bit
>   Exiv2                  -> 0.28.7
>   Lensfun                -> 0.3.4
>   Debug                  -> DISABLED
>   SSE2 optimizations     -> ENABLED
>   OpenMP                 -> ENABLED
>   OpenCL                 -> ENABLED
>   Lua                    -> DISABLED
>   Colord                 -> ENABLED
>   gPhoto2                -> ENABLED
>   OSMGpsMap              -> ENABLED  - map view is available
>   GMIC                   -> ENABLED  - Compressed LUTs are supported
>   GraphicsMagick         -> ENABLED
>   ImageMagick            -> DISABLED
>   libavif                -> ENABLED
>   libheif                -> ENABLED
>   libjxl                 -> ENABLED
>   LibRaw                 -> ENABLED  - Version 0.22.0-Release
>   OpenJPEG               -> ENABLED
>   OpenEXR                -> ENABLED
>   WebP                   -> ENABLED

I'll get a darktable build with Lua enabled and test it with that.
Comment 6 caulier.gilles 2026-04-21 05:45:42 UTC
Right. LUA is used by digiKam to pass all the settings to DarkTable.
Comment 7 Wren Falcon 2026-04-21 05:53:48 UTC
Swapped out darktable-2:5.4.1-2 from the official Arch Linux repos for darktable-git (darktable-git-5.5.0.r1007.gd697177169-1) from the AUR, which is configured to build Lua support in, and it resolved my issue both on digiKam 9.0.0 and the 9.1.0 pre-release AppImage. digiKam is able to load the edited image into the image editor window.

Would you still be needing that .CR3?
Comment 8 caulier.gilles 2026-04-21 05:54:40 UTC
Git commit cf823b072131a9391cdee2058dea2790158f7eb6 by Gilles Caulier.
Committed on 21/04/2026 at 05:53.
Pushed by cgilles into branch 'master'.

Add note about the requirement of LUA support in Darktable.

M  +4    -0    setup_application/editor_settings.rst

https://invent.kde.org/documentation/digikam-doc/-/commit/cf823b072131a9391cdee2058dea2790158f7eb6
Comment 9 caulier.gilles 2026-04-21 05:55:43 UTC
No not need the CR3 as the problem is fixed now.