I think you need the file I pointed to for this (gegl-enums.h)
The file gimp-gegl-enum.h was just for 2.8.14 and the state of GEGL at that time ..it does not include definitions of GEGL_ACCESS_xxx which were added later
See https://mail.gnome.org/archives/commits ... 00293.html
and https://mail.gnome.org/archives/commits ... 00295.html
What did it say in the source file you git-cloned? There must have been some include in there, though probably indirect (the source of gimpdrawable-blend.c will probably include something like gegl/gegl.h which then includes a whole heap of other .h files).
Actually it is #include <gegl.h>
Yes the src clone contains a gegl folder with many needed header files. But when i added the gegl-enums.h file you linked into that folder (gegl/gegl-enums.h) and then added #include gegl/gegl-enums.h to the c file it didn't work. Then i placed the gegl-enums.h file in the core folder (where the c file resides) and tried #include "gegl-enums.h" . That didn't work. Hence the reason i tried gimp-gegl-enums.h. Still didn't work though.
You are probably right about the need of the newer gegl-enums.h file i just need to somehow link to it.
Heck i even tried copying the entire gegl folder from my env include directory into the core folder (which already contained the gegl-enums.h file) and added #include "gegl/gegl-enums.h" to the c file and still no go.
I wasn't asked to update GEGL so i don't think that is the problem either.
I also tried #include <gegl-enums.h>