I have found the problem thanks to one of the eDuke32 developers. Here is the
issue:
$ echo $C_INCLUDE_PATH
/gnu/store/x3r6c04n583q3fz7szm32ahycrxgfiz6-profile/include
Compare this value to
$ sdl2-config --cflags
-I/gnu/store/4bhz5xzr39v0kgxf3ipv6kswicrdmkk4-sdl2-2.0.9/include/SDL2
They point to different entries in the store. And the store entry provided by
sdl2-config does not contain the header file for SDL Mixer (obviously, since
that one is pointing to the store entry of one package instead of a profile). I
am already using sdl-union as my input:
("sdl-union" ,(sdl-union (list sdl2 sdl2-mixer)))
The makefile uses the output of sdl2-config as part of the compiler flags, so
the
include path points into the wrong directory. Is there a way to get sdl2-config
to print the correct path?
