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("includeWatching")) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Use include_watching");
            }
            if (options.exists("lockUnspents")) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Use lock_unspents");
            }
            if (options.exists("subtractFeeFromOutputs")) {
                throw JSONRPCError(RPC_INVALID_PARAMETER, "Use subtract_fee_from_outputs");
            }
            const bool psbt_opt_in = options.exists("psbt") && options["psbt"].get_bool();
            CAmount fee;
            int change_position;
            bool rbf = pwallet->m_signal_rbf;
            if (options.exists("replaceable")) {
                rbf = options["replaceable"].get_bool();
            }
            CMutableTransaction rawTx = ConstructTransaction(options["inputs"], request.params[0], options["locktime"], rbf);
            CCoinControl coin_control;
            
            
            coin_control.m_add_inputs = rawTx.vin.size() == 0;
            FundTransaction(pwallet, rawTx, fee, change_position, options, coin_control);
            bool add_to_wallet = true;
            if (options.exists("add_to_wallet")) {
                add_to_wallet = options["add_to_wallet"].get_bool();
            }
            
            PartiallySignedTransaction psbtx(rawTx);
            
            bool complete = true;