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
```
CScriptID id;
                    CRIPEMD160().Write(whash.begin(), whash.size()).Finalize(id.begin());
                    CScript witnessScript;
                    if (provider->GetCScript(id, witnessScript)) {
                        entry.pushKV("witnessScript", HexStr(witnessScript));
                    }
                }
            }
        }
        entry.pushKV("scriptPubKey", HexStr(scriptPubKey));
        entry.pushKV("amount", ValueFromAmount(out.tx->tx->vout[out.i].nValue));
        entry.pushKV("confirmations", out.nDepth);
        entry.pushKV("spendable", out.fSpendable);
        entry.pushKV("solvable", out.fSolvable);
        if (out.fSolvable) {
            std::unique_ptr<SigningProvider> provider = pwallet->GetSolvingProvider(scriptPubKey);
            if (provider) {
                auto descriptor = InferDescriptor(scriptPubKey, *provider);
                entry.pushKV("desc", descriptor->ToString());
            }
        }
        if (avoid_reuse) entry.pushKV("reused", reused);
        entry.pushKV("safe", out.fSafe);
        results.push_back(entry);
    }
    return results;
},
    };
}
void FundTransaction(CWallet* const pwallet, CMutableTransaction& tx, CAmount& fee_out, int& change_position, const UniValue& options, CCoinControl& coinControl)