Custom folder for storing photos doesn't work for empty folders
When I have project with custom folder for storing photos in QGIS, and this folder is empty, it is not synchronized to mergin, and also to INPUT. When creating a photo feature in INPUT, it shows and error "Cannot copy a photo to working directory"
We should synchronize the empty directory, or INPUT should be able to create a directory in case it is needed. For testing you can use project input-testing/tc10_custom_photo_directory
Here is configuration of the photo field in the feature

This doesn't work out for me. Have been trying to create a empty directory 'photos'. It will be created at local but not in mergin.
In this particular case the problem is in incorrect configuration of the attachment widget. Expression should be set using data-defined override, not entered directly in the field.
is mergin plugin in QGIS reporting the warning?
@jozef-budac @PatrikMizera can you guys try to reproduce this issue? We could not reproduce it. It seems that it is fixed now
@tomasMizera With @iiLubos patch, this issue is solved