If we do tests in a loop, it seems we don't have an easy way to prompt which iteration failed

Do you have any advice for such user cases?

```c
int input[] = {1, 2, 3, 4};
int output[] = {1, 2, 3, 4};
for (int i = 0; i < 4, i++) {
  // ...
  CHECK_EQ(result, output[i]);
}
```
