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 
{
    
    static std::atomic<bool> latchToFalse{false};
    
    if (latchToFalse.load(std::memory_order_relaxed))
        return false;
    LOCK(cs_main);
    if (latchToFalse.load(std::memory_order_relaxed))
        return false;
    if (fImporting || fReindex)
        return true;
    if (chainActive.Tip() == nullptr)
        return true;
    if (chainActive.Tip()->nChainWork < nMinimumChainWork)
        return true;
    if (chainActive.Tip()->GetBlockTime() < (GetTime() - nMaxTipAge))
        return true;
    LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
    latchToFalse.store(true, std::memory_order_relaxed);
    return false;
}
CBlockIndex *pindexBestForkTip = nullptr, *pindexBestForkBase = nullptr;
static void AlertNotify(const std::string& strMessage)