There's still (at least) one error in ht_test.c:

ht_test.c:58:39: error: ‘%lld’ directive output may be truncated writing
between 1 and 19 bytes into a region of size 16 [-Werror=format-truncation=]
   snprintf((char *)key, sizeof(key), "%lld", i);
ht_test.c:58:38: note: directive argument in the range [1,
9223372036854775806]
   snprintf((char *)key, sizeof(key), "%lld", i);
                                      ^~~~~~