[Possible bug] Unknown type compilation error

[CblPOK-git]

` #include <nil/crypto3/hash/algorithm/hash.hpp>
#include <nil/crypto3/hash/sha2.hpp>

using namespace nil::crypto3;

[[circuit]] bool sha256_example(typename hashes::sha2<256>::block_type block0,
                                                          typename hashes::sha2<256>::block_type block1) {

    typename algebra::curves::pallas::base_field_type::value_type a = block0[0];
    typename algebra::curves::pallas::base_field_type::value_type b = block1[0];
    a = a + b;

    return a < b;

}`