in C files where GLFW is included, #define GLFW_INCLUDE_NONE before GLFW is included in that file, because GLFW tries looking for <GL/gl.h> header otherwise, which is not on my system

ffi/glfw-export.c

@@ -1,6 +1,6 @@
-#include "export.h"
-#include <GLFW/glfw3.h>
 #include <stdbool.h>
+#define GLFW_INCLUDE_NONE
+#include <GLFW/glfw3.h>
 
 // GLFW constants used below
 int CONTEXT_VERSION_MAJOR = GLFW_CONTEXT_VERSION_MAJOR;

ffi/glfw-input.c

@@ -1,4 +1,5 @@
 #include "export.h"
+#define GLFW_INCLUDE_NONE
 #include <GLFW/glfw3.h>
 
 int PRESS = GLFW_PRESS;