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 
};
/**
 * Used to track blocks whose transactions were applied to the UTXO state as a
 * part of a single ActivateBestChainStep call.
 *
 * This class also tracks transactions that are removed from the mempool as
 * conflicts (per block) and can be used to pass all those transactions
 * through SyncTransaction.
 *
 * This class assumes (and asserts) that the conflicted transactions for a given
 * block are added via mempool callbacks prior to the BlockConnected() associated
 * with those transactions. If any transactions are marked conflicted, it is
 * assumed that an associated block will always be added.
 *
 * This class is single-use, once you call GetBlocksConnected() you have to throw
 * it away and make a new one.
 */
class ConnectTrace {