Reported here: https://github.com/bitcoin/bitcoin/pull/10244#issuecomment-378035305

Travis log here: https://travis-ci.org/bitcoin/bitcoin/jobs/361243719#L2810

Note the JSON exception:

```
test_framework.authproxy.JSONRPCException: The mempool was not loaded yet (-1) 
```

That exception was introduced here: https://github.com/bitcoin/bitcoin/commit/cb1e319fe9e198c9c5cf5236fe9af5a3d748b9e8#diff-a0c8f511d90e83aa9b5857e819ced344R1617

cc @jtimon 
}
            }
        }
    }
    if (maxFeeRateRemoved > CFeeRate(0)) {
        LogPrint(BCLog::MEMPOOL, "Removed %u txn, rolling minimum fee bumped to %s\n", nTxnRemoved, maxFeeRateRemoved.ToString());
    }
}
uint64_t CTxMemPool::CalculateDescendantMaximum(txiter entry) const {
    
    std::vector<txiter> candidates;
    setEntries counted;
    candidates.push_back(entry);
    uint64_t maximum = 0;
    while (candidates.size()) {
        txiter candidate = candidates.back();
        candidates.pop_back();
        if (!counted.insert(candidate).second) continue;
        const setEntries& parents = GetMemPoolParents(candidate);
        if (parents.size() == 0) {
            maximum = std::max(maximum, candidate->GetCountWithDescendants());
        } else {
            for (txiter i : parents) {
                candidates.push_back(i);
            }
        }
    }
    return maximum;
}
void CTxMemPool::GetTransactionAncestry(const uint256& txid, size_t& ancestors, size_t& descendants) const {