error.c: (mrb_exc_new) use `mrb_int` instead of `size_t`.
MODIFY
include/mruby.h
include/mruby.h
@@ -1338,7 +1338,7 @@ MRB_API mrb_value mrb_obj_clone(mrb_state *mrb, mrb_value self);
#define TOLOWER(c) (ISUPPER(c) ? ((c) | 0x20) : (c))
#endif
-MRB_API mrb_value mrb_exc_new(mrb_state *mrb, struct RClass *c, const char *ptr, size_t len);
+MRB_API mrb_value mrb_exc_new(mrb_state *mrb, struct RClass *c, const char *ptr, mrb_int len);
MRB_API mrb_noreturn void mrb_exc_raise(mrb_state *mrb, mrb_value exc);
MRB_API mrb_noreturn void mrb_raise(mrb_state *mrb, struct RClass *c, const char *msg);

MODIFY
src/error.c
src/error.c
@@ -59,7 +59,7 @@ mrb_exc_new_str(mrb_state *mrb, struct RClass* c, mrb_value str)
}
MRB_API mrb_value
-mrb_exc_new(mrb_state *mrb, struct RClass *c, const char *ptr, size_t len)
+mrb_exc_new(mrb_state *mrb, struct RClass *c, const char *ptr, mrb_int len)
{
return mrb_exc_new_str(mrb, c, mrb_str_new(mrb, ptr, len));
}

error.c: (mrb_exc_new) use `mrb_int` instead of `size_t`.