groth16.Verify Resulting In sigpanic: panicmem

[Kasshern]

When running

`func CallCubicCircuit() string {
var zkcircuit Circuit
r1cs, err := frontend.Compile(ecc.BN254, backend.GROTH16, &zkcircuit)
if err != nil {
log.Fatal(err)
}

// generating pk, vk
assignment := &Circuit{
	X: 42,
	Y: 42,
}

witness, _ := frontend.NewWitness(assignment, ecc.BN254)
publicWitness, err := witness.Public()
pk, vk, err := groth16.Setup(r1cs)
proof, err := groth16.Prove(r1cs, pk, witness)
err = groth16.Verify(proof, vk, publicWitness)
if err != nil {
	return "INVALID PROOF!"
} else {
	return "VALID PROOF"
}`

I get the following Stack Trace

C:/Program Files/Go/src/runtime/panic.go:221 (0x7c9b9c)
panicmem: panic(memoryError)
C:/Program Files/Go/src/runtime/signal_windows.go:254 (0x7c9b6c)
sigpanic: panicmem()
C:/Users/.../go/pkg/mod/github.com/consensys/gnark@v0.6.4/internal/backend/bn254/groth16/prove.go:47 (0xcbac19)
(*Proof).isValid: return proof.Ar.IsInSubGroup() && proof.Krs.IsInSubGroup() && proof.Bs.IsInSubGroup()
C:/Users/.../go/pkg/mod/github.com/consensys/gnark@v0.6.4/internal/backend/bn254/groth16/verify.go:45 (0xcc0ad5)
Verify: if !proof.isValid() {
C:/Users/.../go/pkg/mod/github.com/consensys/gnark@v0.6.4/backend/groth16/groth16.go:137 (0xcdb184)
Verify: return groth16_bn254.Verify(_proof, vk.(*groth16_bn254.VerifyingKey), *w)
C:/Users/.../zkcircuits/cubic/cubic.go:46 (0xcdc164)
CallCubicCircuit: err = groth16.Verify(proof, vk, publicWitness)
C:/Users/.../zkcircuits/main.go:35 (0xe32407)

if X and Y are the correct values the proof returns valid as expected

Anyone know whats up with this invalid memory address or nil pointer deference?

[gbotrel]

hi -- from the snippet, it seems you're not checking the Prover error;

proof, err := groth16.Prove(r1cs, pk, witness)

// missing error check here 

err = groth16.Verify(proof, vk, publicWitness)
if err != nil {
	return "INVALID PROOF!"
} else {
	return "VALID PROOF"
}

[Kasshern]

Thank you works like a charm now.