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 
{
    FlatFilePos block_pos;
    {
        LOCK(cs_main);
        block_pos = pindex->GetBlockPos();
    }
    return ReadRawBlockFromDisk(block, block_pos, message_start);
}
CAmount GetBlockSubsidy(int nHeight, const Consensus::Params& consensusParams)
{
    int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
    
    if (halvings >= 64)
        return 0;
    CAmount nSubsidy = 50 * COIN;
    
    nSubsidy >>= halvings;
    return nSubsidy;
}
bool IsInitialBlockDownload()