Gimp 2.10 has been released:
https://www.gimp.org/news/2018/04/27/gimp-2-10-0-released/One big improvement relevant to CHDK users is support for > 8bpp depth, so you can export full precision 16 bit tiff or png from your raw software instead of being forced to work with lower precision.
I've used development and RC builds a bit and didn't run into major problems.
