Unable to deploy a Liquidity smart contract directly (without offline signature / forged operation)

Question

I'm trying to deploy a contract directly as specified in Liquidity docs, but the CLI fails with:

Failure: edsk3gUfUPyBSfrS9CCgmCiQsTCHGkviBDusMxDJstFtojtc1zcpsh is not a valid private key

I have tried with a combination of different private keys / sources, without any luck. Does anyone know how to deploy a Liquidity contract without forging a local operation (through the Liquidity CLI).

Github issue