Requested PR changes for #310 (2)

zero_bin/common/src/prover_state/persistence.rs

@@ -28,15 +28,15 @@ const ZK_EVM_CACHE_DIR_ENV: &str = "ZK_EVM_CACHE_DIR";
 /// We version serialized circuits by the kernel hash they were serialized with,
 /// but we really only need a few of the starting hex nibbles to reliably
 /// differentiate.
-const NUM_HASH_NIBS_TO_USE_IN_CIRCUIT_VERSION: usize = 8;
+const KERNEL_HASH_PREFIX: usize = 8;
 
 /// When we serialize/deserialize circuits, we rely on the hash of the plonky
 /// kernel to determine if the circuit is compatible with our current binary. If
 /// the kernel hash of the circuit that we are loading in from disk differs,
 /// then using these circuits could potentially lead to incorrect results (but
 /// most likely just a crash).
 pub static CIRCUIT_VERSION: Lazy<String> =
-    Lazy::new(|| hex::encode(KERNEL.hash())[..NUM_HASH_NIBS_TO_USE_IN_CIRCUIT_VERSION].to_string());
+    Lazy::new(|| hex::encode(KERNEL.hash())[..KERNEL_HASH_PREFIX].to_string());
 
 fn get_serializers() -> (
     DefaultGateSerializer,

zero_bin/leader/src/main.rs

@@ -1,4 +1,4 @@
-use std::io;
+use std::{env, io};
 use std::{fs::File, path::PathBuf};
 
 use anyhow::Result;