Hello again. Rebuilt gimp again. Now gmic_gimp compile ends with this error:
gmic_gimp_gtk.cpp:407:33: error: ‘GIMP_LAYER_MODE_HSV_COLOR_LEGACY’ was not declared in this scope
** #define GIMP_COLOR_MODE GIMP_LAYER_MODE_HSV_COLOR_LEGACY**
I’ll keep trying every day or so with updated gimp builds to see if anything changes.