Have this warning while building current master (0bd4929cd00e91bf4137f43b097cd62f72f503e4) on one test machine.
```
wallet/rpcwallet.cpp: In function 'rescanblockchain()::<lambda(const RPCHelpMan&, const JSONRPCRequest&)>':
wallet/rpcwallet.cpp:3596:19: warning: '*((void*)& stop_height +4)' may be used uninitialized in this function [-Wmaybe-uninitialized]
 3596 |     Optional<int> stop_height;
      |                   ^~~~~~~~~~~
```
```
$ gcc --version
gcc (Gentoo 9.2.0-r2 p3) 9.2.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ uname -a
Linux red-box 4.19.72-gentoo #2 SMP Sun Sep 22 03:00:01 EEST 2019 x86_64 Intel(R) Pentium(R) CPU N3710 @ 1.60GHz GenuineIntel GNU/Linux
```
if (options.exists("minimumSumAmount"))
            nMinimumSumAmount = AmountFromValue(options["minimumSumAmount"]);
        if (options.exists("maximumCount"))
            nMaximumCount = options["maximumCount"].get_int64();
    }
    
    
    pwallet->BlockUntilSyncedToCurrentChain();
    UniValue results(UniValue::VARR);
    std::vector<COutput> vecOutputs;
    {
        CCoinControl cctl;
        cctl.m_avoid_address_reuse = false;
        cctl.m_min_depth = nMinDepth;
        cctl.m_max_depth = nMaxDepth;
        LOCK(pwallet->cs_wallet);
        pwallet->AvailableCoins(vecOutputs, !include_unsafe, &cctl, nMinimumAmount, nMaximumAmount, nMinimumSumAmount, nMaximumCount);
    }
    LOCK(pwallet->cs_wallet);
    const bool avoid_reuse = pwallet->IsWalletFlagSet(WALLET_FLAG_AVOID_REUSE);
    for (const COutput& out : vecOutputs) {
        CTxDestination address;
        const CScript& scriptPubKey = out.tx->tx->vout[out.i].scriptPubKey;
        bool fValidAddress = ExtractDestination(scriptPubKey, address);
        bool reused = avoid_reuse && pwallet->IsSpentKey(out.tx->GetHash(), out.i);
        if (destinations.size() && (!fValidAddress || !destinations.count(address)))
            continue;
        UniValue entry(UniValue::VOBJ);
        entry.pushKV("txid", out.tx->GetHash().GetHex());
        entry.pushKV("vout", out.i);