Re: nargo execute. Is it possible to just generate witnesses without recompiling circuit?

[ihyunnam]

Hi, I'm wondering if it's possible to just generate witnesses (Prover.toml is already populated) without recompiling an already compiled circuit. I'm running nargo compile first which compiles the circuit and creates the circuit_name.json file. Then, I want to make multiple proofs of the same circuit with just different inputs. Hence, I only need to create witnesses from here on; recompiling the circuit will add to runtime, which I'm trying to optimize for.

However, it seems like nargo execute automatically recompiles the circuit and creates witnesses. Is this true? If so, is there a separate CLI command that strictly only generates witnesses? Or does nargo execute only recompile the circuit if there are changes to the circuit configuration, otherwise not adding to the runtime?

[TomAFrench]

Hi @ihyunnam, yes I agree that the current behaviour isn't ideal.

You're correct that if you're not making changes to your circuit then by default nargo execute will short-circuit compilation after monomorphisation once we've checked that you'd be regenerating the same artifact as before. Repeatedly calling nargo execute should have a relatively low compilation overhead.

We'd like to fully separate execution from compilation however, so we also have a noir-execute binary which will directly consume a noir build artifact https://github.com/noir-lang/noir/blob/master/tooling/artifact_cli/

This isn't currently distributed in our releases but if you compile from source then you can make use of this.