While doing some edits in darktable 2.7 git d5716a, this suddenly appeared in front of me.
Exporting works fine, this seems to be affecting only the display frame.
Anyway, I leave it here for the records, since I really liked it.
I don’t know how to reproduce the steps that led to this, so I won’t fill a bug.
As for the original image, I was trying to do a monochrome with a dark sky and was getting issues regarding the sculpture, if I may name it so, probably because of masking x chromatic aberrations.
IMG_5661_01.cr2.xmp (2.7 KB)
(CC BY-NC 4.0)