```
bitcoind -par=1
```

Excerpt from the `debug.log`:

```
Using 0 threads for script verification
```

Zero? I guess not ;)
nLocalServices = ServiceFlags(nLocalServices | NODE_WITNESS);
    }
    
    if (!CheckDiskSpace(GetDataDir())) {
        InitError(strprintf(_("Error: Disk space is low for %s").translated, GetDataDir()));
        return false;
    }
    if (!CheckDiskSpace(GetBlocksDir())) {
        InitError(strprintf(_("Error: Disk space is low for %s").translated, GetBlocksDir()));
        return false;
    }
    
    
    boost::signals2::connection block_notify_genesis_wait_connection;
    if (::ChainActive().Tip() == nullptr) {
        block_notify_genesis_wait_connection = uiInterface.NotifyBlockTip_connect(BlockNotifyGenesisWait);
    } else {
        fHaveGenesis = true;
    }
#if HAVE_SYSTEM
    if (gArgs.IsArgSet("-blocknotify"))
        uiInterface.NotifyBlockTip_connect(BlockNotifyCallback);
#endif
    std::vector<fs::path> vImportFiles;
    for (const std::string& strFile : gArgs.GetArgs("-loadblock")) {
        vImportFiles.push_back(strFile);
    }
    threadGroup.create_thread(std::bind(&ThreadImport, vImportFiles));