This makes me think that you're using single-header libraries wrong. These kind of libraries usually require you to do something special prior to including it to get the actual code and you must do it only in ONE file.
For example, you'd #define RGFW_IMPLEMENTATION before #include rgfw.h in exactly ONE .c. If you need the header in other files, you do NOT define RGFW_IMPLEMENTATION and no code will be produced.
In any case, forcing me to figure out the specific XYZ_IMPLEMENTATION for each library is less user friendly that just proving a .c and .h file.
But after being burned a few times by naming or linking conflicts or you cloned your .c and forgot to remove the #define and now you have two implementations or having to debug any BSS/DATA/TEXT issues (because now lib and user code end up in the same .o and the linker can't do its magic for your esoteric architecture), I just took the habit of always manually creating a matching .c that only contains:
#define BLAH_IMPLEMENTATION
#include "blah.h"The single-header format also gives you MORE ways to compile the library and control which features to use or not use.
#include "impl.c"
#define XZUGG_IMPL
#include "impl.h"