Minimal constraint trace fail

poseidon-tornado/src/main.rs

@@ -7,13 +7,40 @@ use ark_groth16::{
     create_random_proof as prove, generate_random_parameters, prepare_verifying_key, verify_proof,
 };
 
+// Tracing
+use tracing::{span, event, Level};
+use ark_relations::r1cs::{ConstraintTrace, ConstraintLayer, ConstraintSystem, TracingMode};
+use tracing_subscriber::layer::SubscriberExt;
+
+
 fn groth16_proof_example() -> Result<()> {
+    println!("Circom 1");
+
+    // Tracing to help with debugging
+    let mut layer = ConstraintLayer::default();
+    layer.mode = TracingMode::OnlyConstraints;
+    let subscriber = tracing_subscriber::Registry::default().with(layer);
+    let _guard = tracing::subscriber::set_default(subscriber);
+
+    let trace = ConstraintTrace::capture();
+    println!("Trace is: {:?}", trace);
+
     let cfg = CircomConfig::<Bn254>::new(
         "./resources/withdraw.wasm",
         "./resources/withdraw.r1cs",
     )?;
 
+    // Test
+    let trace = ConstraintTrace::capture();
+    println!("Trace is: {:?}", trace);
+
+    println!("Circom 2");
     let mut builder = CircomBuilder::new(cfg);
+
+
+    println!("Circom 3");
+    // XXX Here - probably is inputs don't match,
+    // but would like the tracing to tell me this
     builder.push_input("a", 3);
     builder.push_input("b", 11);