We pass 2 GeglColor through the wire now. Since it is passed very early
(when sharing the configuration), I had some issues with initialization
order of GEGL, and in particular when calling gegl_init() before
gegl_config() inside _gimp_config(), I had a bunch of such criticals:
> Plugin script-fu: GLib-GObject: CRITICAL: Two different plugins tried to register 'GeglOpPlugIn-transform-core'
Anyway in the end, I store the passed colors as raw bytes and strings in
the GPConfig object, and re-construct the GeglColor last minute in
_gimp_config().
Our meson build system was not properly building the enums.c file,
because they are versionned.
I did a similar trick as what I did for the pdbgen, which is that I used
a wrapper script around the existing perl script, which sets proper
options and generate a stamp file in the end (which is considered by
meson as the actual custom target, not the C file since it is generated
in the source dir).
The most important part is that the stamp file is a generated header
source (not just a random text file) which is **included** by the
generated C file. This is what will force meson to regenerate the C file
if the header is updated, **then** build using this new version, not use
an outdated versionned version (which would make for hard to diagnose
bugs), through the indirection of the intermediate stamp header.
See #4201.
See also: https://github.com/mesonbuild/meson/issues/10196#issuecomment-1080742592