if (a_len != b_len || memcmp (a, b, a_len) != 0)
{
- fprintf (stderr, "consecutive gzwrites are different: lengths %i and %i\n", a_len, b_len);
+ fprintf (stderr, "consecutive gzwrites are different: lengths %zu and %zu\n", a_len, b_len);
return 1;
}