Image previews are not generated for .HEIC files, despite having the appropriate libraries installed.
STEPS TO REPRODUCE
1. Install package "heif-thumbnailer".
2. Create some .HEIC images.
3. Enable image previews in dolphin.
4. Go to the folder with the .HEIC images in dolphin.
5. Configure dolphin to show previews of the images in that folder.
No previews are shown.
Should show previews of the images from their thumbnails.
Operating System: Debian GNU/Linux
KDE Plasma Version: 5.24.3
KDE Frameworks Version: 5.90.0
Qt Version: 5.15.2
Kernel Version: 5.16.0-5-amd64 (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 2700 Eight-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: AMD VEGA10
*** This bug has been marked as a duplicate of bug 444976 ***