act.obj2.c: In function ‘weight_change_object’:
act.obj2.c:51:3: warning: implicit declaration of function ‘log’ [-Wimplicit-function-declaration]
   51 |   log("Unknown attempt to subtract weight from an object.");
      |   ^~~
act.obj2.c:51:3: warning: incompatible implicit declaration of built-in function ‘log’
act.obj2.c:18:1: note: include ‘<math.h>’ or provide a declaration of ‘log’
   17 | #include "spells.h"
  +++ |+#include <math.h>
   18 | 
act.obj2.c:51:7: error: incompatible type for argument 1 of ‘log’
   51 |   log("Unknown attempt to subtract weight from an object.");
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |       |
      |       char *