Current bitcoin-master on testnet, `maxconnections=8` in the config file. Running in VM that doesn't have public IP and is not reachable from the Internet.

Wait until you have 8 peers.

```
telnet localhost 18333
```

It will result in:

```
Assertion failed: (nMaxInbound > 0), function AcceptConnection, file net.cpp, line 973.
```

First found in https://github.com/bitcoin/bitcoin/pull/8996, but can be reproduced on master.

{
    
    
    
    
    if ((addrman.size() > 0) &&
        (!GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED))) {
        MilliSleep(11 * 1000);
        LOCK(cs_vNodes);
        int nRelevant = 0;
        for (auto pnode : vNodes) {
            nRelevant += pnode->fSuccessfullyConnected && ((pnode->nServices & nRelevantServices) == nRelevantServices);
        }
        if (nRelevant >= 2) {
            LogPrintf("P2P peers available. Skipped DNS seeding.\n");
            return;
        }
    }
    const std::vector<CDNSSeedData> &vSeeds = Params().DNSSeeds();
    int found = 0;
    LogPrintf("Loading addresses from DNS seeds (could take a while)\n");
    BOOST_FOREACH(const CDNSSeedData &seed, vSeeds) {