Font not loaded

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

Hello,

I use:

• Linux 5.15.0-161-generic
• Mint 21.3
• Cinnamon 6.0.4
• Darktable 5.2.1 via Flatpack

I suddenly have little squares instead of characters throughout the interface.

I didn't change anything about the fonts. The only thing I can say is that, just before it happened, I had several crashes with the database locked (this has been happening very often when I export photos for the last 3 or 4 versions).

Steps to reproduce

1. Launch Darktable
2. See squares everywhere

Expected behavior

Display the right font

Logfile | Screenshot | Screencast

Screenshot: https://acloud6.zaclys.com/index.php/apps/photos/public/8k77wSW1mYYjkCNa7dmBXIvVvLgo6T9K

If I run: flatpak run org.darktable.Darktable -d common
I got this:

 darktable 5.2.1
 Copyright (C) 2012-2025 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                    -> ENABLED  - API version 9.5.0
   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-Devel202502
   OpenJPEG               -> ENABLED
   OpenEXR                -> ENABLED
   WebP                   -> ENABLED

 See https://www.darktable.org/resources/ for detailed documentation.
 See https://github.com/darktable-org/darktable/issues/new/choose to report bugs.

 0.0001 [dt starting]
  darktable -d common
 0.0002 application_directory: /app/bin
 0.0002 darktable.datadir: /app/share/darktable
 0.0002 darktable.plugindir: /app/lib/darktable
 0.0002 darktable.localedir: /app/share/locale
 0.0003 darktable.sharedir: /app/share
 0.0003 darktable.configdir: /home/myname/.var/app/org.darktable.Darktable/config/darktable
 0.0003 darktable.cachedir: /home/myname/.var/app/org.darktable.Darktable/cache/darktable
 0.0003 darktable.tmpdir: /tmp
 0.0003 new_xdg_data_dirs: (null)
 Gtk-Message: 17:53:36.873: Failed to load module "xapp-gtk3-module"

 (darktable:2): Pango-WARNING **: 17:53:37.085: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 10'

 (darktable:2): Pango-WARNING **: 17:53:37.085: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.085: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.087: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 12.5'

 (darktable:2): Pango-WARNING **: 17:53:37.087: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.087: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.088: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 15'

 (darktable:2): Pango-WARNING **: 17:53:37.088: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.088: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.090: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 18.75'

 (darktable:2): Pango-WARNING **: 17:53:37.090: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.090: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.091: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 48'

 (darktable:2): Pango-WARNING **: 17:53:37.091: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.091: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.092: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 60'

 (darktable:2): Pango-WARNING **: 17:53:37.092: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:37.092: scaled_font status is: file not found
      0,8201 [dt_worker_threads] using 7 worker threads
      0,8846 [dt_get_sysresource_level] switched to `default'
      0,8846   total mem:       7815MB
      0,8846   available mem:   3907MB
      0,8846   singlebuff:      61MB
      0,8846   mipmap cache:    976MB
      0,9029 [opencl_init] opencl disabled via darktable preferences
      0,9030 [dt_dlopencl_init] could not find default opencl runtime library 'libOpenCL'
      0,9031 [dt_dlopencl_init] could not find default opencl runtime library 'libOpenCL.so'
      0,9032 [opencl_init] opencl library 'libOpenCL.so.1' found on your system and loaded, preference 'default path'
 pci id for fd 26: 10de:1c91, driver (null)
 pci id for fd 27: 10de:1c91, driver (null)
      0,9922 [opencl_init] found 2 platforms
      0,9922 [check platform] platform 'rusticl' with key 'clplatform_rusticl' is NOT active
 [opencl_init] found 1 device

 [dt_opencl_device_init]
    DEVICE:                   0: 'NVIDIA GeForce GTX 1050'
    CONF KEY:                 cldevice_v5_nvidiacudanvidiageforcegtx1050
    PLATFORM, VENDOR & ID:    NVIDIA CUDA, NVIDIA Corporation, ID=4318
    CANONICAL NAME:           nvidiacudanvidiageforcegtx1050
    DRIVER VERSION:           470.256.02
    DEVICE VERSION:           OpenCL 3.0 CUDA, SM_20 SUPPORT
    DEVICE_TYPE:              GPU, dedicated mem
    GLOBAL MEM SIZE:          3020 MB
    MAX MEM ALLOC:            755 MB
    MAX IMAGE SIZE:           16384 x 32768
    MAX WORK GROUP SIZE:      1024
    MAX WORK ITEM DIMENSIONS: 3
    MAX WORK ITEM SIZES:      [ 1024 1024 64 ]
    ASYNC PIXELPIPE:          NO
    PINNED MEMORY TRANSFER:   NO
    AVOID ATOMICS:            NO
    MICRO NAP:                250
    ROUNDUP WIDTH & HEIGHT    16x16
    CHECK EVENT HANDLES:      128
    TILING ADVANTAGE:         0,000
    DEFAULT DEVICE:           NO
    KERNEL BUILD DIRECTORY:   /app/share/darktable/kernels
    KERNEL DIRECTORY:         /home/myname/.var/app/org.darktable.Darktable/cache/darktable cached_v5_kernels_for_NVIDIACUDANVIDIAGeForceGTX1050_47025602
    CL COMPILER OPTION:       -cl-fast-relaxed-math
    CL COMPILER COMMAND:      -w -cl-fast-relaxed-math -DNVIDIA_SM_20=1 -DNVIDIA=1 -I"/app/share/darktable/kernels"
    CL EXCEPTION:             DT_OPENCL_ONLY_CUDA
    KERNEL LOADING TIME:       0,0250 sec
 [opencl_init] OpenCL successfully initialized. internal numbers and names of available devices:
 [opencl_init]		0	'NVIDIA CUDA NVIDIA GeForce GTX 1050'
      1,0840 [opencl_init] FINALLY: opencl PREFERENCE=OFF is AVAILABLE and NOT ENABLED.
 [opencl_update_priorities] these are your device priorities:
 [opencl_update_priorities] 		image	preview	export	thumbs	preview2
 [dt_opencl_update_priorities]		0	-1	0	0	-1
 [opencl_update_priorities] show if opencl use is mandatory for a given pixelpipe:
 [opencl_update_priorities] 		image	preview	export	thumbs	preview2
 [opencl_update_priorities]		0	0	0	0	0
 [opencl_synchronization_timeout] synchronization timeout set to 200
 [opencl_update_priorities] these are your device priorities:
 [opencl_update_priorities] 		image	preview	export	thumbs	preview2
 [dt_opencl_update_priorities]		0	-1	0	0	-1
 [opencl_update_priorities] show if opencl use is mandatory for a given pixelpipe:
 [opencl_update_priorities] 		image	preview	export	thumbs	preview2
 [opencl_update_priorities]		0	0	0	0	0
 [opencl_synchronization_timeout] synchronization timeout set to 200
      1,1248 [dt_worker_threads] using 7 worker threads

 (darktable:2): Pango-WARNING **: 17:53:39.037: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 10'

 (darktable:2): Pango-WARNING **: 17:53:39.037: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.037: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.882: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light Italic 10'

 (darktable:2): Pango-WARNING **: 17:53:39.882: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.882: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.883: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light Italic 12.5'

 (darktable:2): Pango-WARNING **: 17:53:39.883: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.883: scaled_font status is: file not found
 3,0796 [dt_worker_threads] using 7 worker threads

 (darktable:2): Pango-WARNING **: 17:53:39.994: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Condensed, 10.999'

 (darktable:2): Pango-WARNING **: 17:53:39.994: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.994: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.995: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Condensed, 13.749'

 (darktable:2): Pango-WARNING **: 17:53:39.995: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.995: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.997: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Bold 10'

 (darktable:2): Pango-WARNING **: 17:53:39.997: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.997: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.998: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Bold 12.5'

 (darktable:2): Pango-WARNING **: 17:53:39.998: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:39.998: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.005: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Medium 10'

 (darktable:2): Pango-WARNING **: 17:53:40.005: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.005: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.006: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Medium 12.5'

 (darktable:2): Pango-WARNING **: 17:53:40.006: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.006: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.348: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 13.199'

 (darktable:2): Pango-WARNING **: 17:53:40.348: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.348: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.349: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 16.5'

 (darktable:2): Pango-WARNING **: 17:53:40.349: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.349: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.363: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 7.5'

 (darktable:2): Pango-WARNING **: 17:53:40.363: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.363: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.364: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Light 9.375'

 (darktable:2): Pango-WARNING **: 17:53:40.364: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.364: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.420: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Bold 13.125'

 (darktable:2): Pango-WARNING **: 17:53:40.420: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.420: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.421: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto Bold 13.125'

 (darktable:2): Pango-WARNING **: 17:53:40.421: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:40.421: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:41.012: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto 10'

 (darktable:2): Pango-WARNING **: 17:53:41.012: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:41.012: scaled_font status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:41.016: failed to create cairo scaled font, expect ugly output. the offending font is 'Roboto 12.5'

 (darktable:2): Pango-WARNING **: 17:53:41.016: font_face status is: file not found

 (darktable:2): Pango-WARNING **: 17:53:41.016: scaled_font status is: file not found
    136,8536 Session fullpipe cache report. hits/run=0,00, hits/test=0,000
       [opencl_summary_statistics] device 'NVIDIA CUDA NVIDIA GeForce GTX 1050' id=0: NOT utilized

Commit

No response

Where did you obtain darktable from?

Flatpak

darktable version

5.2.1

What OS are you using?

Linux

What is the version of your OS?

Linux 5.15.0-161-generic Mint 21.3 Cinnamon 6.0.4

Describe your system

The font Roboto is well installed on my system. I didn't touch anything about it before the incident.

Are you using OpenCL GPU in darktable?

I dont know

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

I've installed and launched Darktable 3.8.1 with the System Package. Everything works fine, the fonts are here.

Start by reproducing the issue with the Flatpak launch command flatpak run org.darktable.Darktable -d common on the reported Linux environment. Review the Pango warnings for missing Roboto font faces and the screenshot, then trace the desktop font-loading path. Done means the interface displays normal characters instead of squares and the missing-font warnings no longer occur.