GCC doesn't like signed/unsigned comparisons

tests/benchmarkInteractions.c

@@ -238,7 +238,7 @@ void test_interactions(struct part test_part, struct part *parts, size_t count,
   float dx[3 * count] __attribute__((aligned(array_align)));
 
   struct part *piq[count], *pjq[count];
-  for (int k = 0; k < count; k++) {
+  for (size_t k = 0; k < count; k++) {
     piq[k] = NULL; pjq[k] = NULL;
   }