Running master 4d661ba:
```
src/bitcoin-cli combinepsbt [""] or src/bitcoin-cli combinepsbt []
```

```
  * frame #0: 0x000000010016054a bitcoind`PartiallySignedTransaction::PartiallySignedTransaction(PartiallySignedTransaction const&) [inlined] boost::optional_detail::optional_base<CMutableTransaction>::is_initialized(this=0x0000000000000000) const at optional.hpp:394 [opt]
    frame #1: 0x000000010016054a bitcoind`PartiallySignedTransaction::PartiallySignedTransaction(PartiallySignedTransaction const&) [inlined] boost::optional_detail::optional_base<CMutableTransaction>::optional_base(this=<unavailable>, rhs=0x0000000000000000) at optional.hpp:196 [opt]
    frame #2: 0x0000000100160542 bitcoind`PartiallySignedTransaction::PartiallySignedTransaction(PartiallySignedTransaction const&) [inlined] boost::optional<CMutableTransaction>::optional(this=0x000070000b9fe7c0, (null)=0x0000000000000000) at optional.hpp:958 [opt]
    frame #3: 0x0000000100160542 bitcoind`PartiallySignedTransaction::PartiallySignedTransaction(PartiallySignedTransaction const&) [inlined] boost::optional<CMutableTransaction>::optional(this=0x000070000b9fe7c0, (null)=0x0000000000000000) at optional.hpp:958 [opt]
    frame #4: 0x0000000100160542 bitcoind`PartiallySignedTransaction::PartiallySignedTransaction(this=0x000070000b9fe7c0, psbt_in=0x0000000000000000) at sign.h:576 [opt]
    frame #5: 0x0000000100142ae5 bitcoind`combinepsbt(JSONRPCRequest const&) [inlined] PartiallySignedTransaction::PartiallySignedTransaction(this=0x000070000b9fe700, psbt_in=<unavailable>) at sign.h:576 [opt]
    frame #6: 0x0000000100142ae0 bitcoind`combinepsbt(request=<unavailable>) at rawtransaction.cpp:1526 [opt]
    frame #7: 0x0000000100170f0a bitcoind`CRPCTable::execute(this=<unavailable>, request=0x000070000b9fead0) const at server.cpp:557 [opt]
```
return rawTx;
}
static UniValue createrawtransaction(const JSONRPCRequest& request)
{
    if (request.fHelp || request.params.size() < 2 || request.params.size() > 4) {
        throw std::runtime_error(
            RPCHelpMan{"createrawtransaction",
                "\nCreate a transaction spending the given inputs and creating new outputs.\n"
                "Outputs can be addresses or data.\n"
                "Returns hex-encoded raw transaction.\n"
                "Note that the transaction's inputs are not signed, and\n"
                "it is not stored in the wallet or transmitted to the network.\n",
                {
                    {"inputs", RPCArg::Type::ARR,  false,  "", "A json array of json objects",
                        {
                            {"", RPCArg::Type::OBJ,  true,  "", "",
                                {
                                    {"txid", RPCArg::Type::STR_HEX,  false,  "", "The transaction id"},
                                    {"vout", RPCArg::Type::NUM,  false,  "", "The output number"},
                                    {"sequence", RPCArg::Type::NUM,  true,  "depends on the value of the 'replaceable' and 'locktime' arguments", "The sequence number"},
                                },
                                },
                        },
                        },
                    {"outputs", RPCArg::Type::ARR,  false,  "", "a json array with outputs (key-value pairs), where none of the keys are duplicated.\n"
                            "That is, each address can only appear once and there can only be one 'data' object.\n"
                            "For compatibility reasons, a dictionary, which holds the key-value pairs directly, is also\n"
                            "                             accepted as second parameter.",
                        {
                            {"", RPCArg::Type::OBJ,  true,  "", "",