Empty txInfoSignatories after building transaction with cardano-cli

Question

In the Plutus Pionner Lectures, Lars instructed us to use txSignedBy in order to ensure that a user signed the transaction. The function tries to find a public key hash in the txInfoSignatories list, if it's able to find, it returns True.

Everything was working in the emulator, but now, when I tried to manually build and sign the transaction with cardano-cli, the transaction doesn't appear to add the public key hash from the user who signed it to txInfoSignatories and the script validation fails. My question is: how do I add the user pubkeyhash to txInfoSignatories with cardano-cli? No information regarding the signature appears when I execute cardano-cli transaction build -- help

Answer 1

------ UPDATE------

Since version 1.31 of cardano-cli, there is the following option to sign the transaction when it is built, so you can avoid that error from the script:

--required-signer FILE   Input filepath of the signing key (zero or more)
                         whose signature is required.

-----------------------

It's related to this bug: Cli to pass required signer (reqSignerHashes) to plutus script for txInfoSignatories

In a near future, there will be a --required-signer option in cardano-cli

As a workaround try to combine toPubKeyHash and txOutAddress function to get the PubKeyHash from any output.

info :: TxInfo
info = scriptContextTxInfo ctx

txOuts :: [TxOut]
txOuts = txInfoOutputs info

outPubKeyHash :: Maybe PubKeyHash
outPubKeyHash = toPubKeyHash $ txOutAddress $ head txOuts

Answer 2

@georgeos answer was correct, but from node version 1.32 there is

--required-signer-hash HASH
                           Hash of the verification key (zero or more) whose
                           signature is required.

(so you don't need to know users signing key, just pass the PubKeyHash)