rusk-prover: Add debug feature to print the test circuit-bytes

This behaviour was lost with the merge of PR #2135

rusk-prover/Cargo.toml

@@ -12,6 +12,10 @@ dusk-plonk = { workspace = true, features = ["rkyv-impl", "alloc"] }
 rusk-profile = { workspace = true }
 execution-core = { workspace = true, features = ["zk"] }
 
+# debug dependency
+hex = { workspace = true, optional = true }
+tracing = { workspace = true, optional = true }
+
 [dev-dependencies]
 hex = { workspace = true }
 
@@ -20,3 +24,4 @@ no_random = []
 std = [
     "dusk-plonk/std"
 ]
+debug = ["hex", "tracing"]

rusk-prover/src/lib.rs

@@ -51,6 +51,12 @@ impl Prove for LocalProver {
         #[cfg(feature = "no_random")]
         let rng = &mut StdRng::seed_from_u64(0xbeef);
 
+        #[cfg(feature = "debug")]
+        tracing::info!(
+            "tx_circuit_vec:\n{}",
+            hex::encode(tx_circuit_vec_bytes)
+        );
+
         let (proof, _pi) = match tx_circuit_vec.input_notes_info.len() {
             1 => TX_CIRCUIT_1_2_PROVER
                 .prove(rng, &create_circuit::<1>(tx_circuit_vec)?)