improve error messages

tools/spectool/src/main.rs

@@ -247,18 +247,18 @@ fn main_generate() {
 
         let mut found_post_check_errors = false;
 
-        for (final_value, required_value) in expected_regs.iter().zip(post.regs.iter()) {
+        for ((final_value, reg), required_value) in expected_regs.iter().zip(Reg::ALL).zip(post.regs.iter()) {
             if let Some(required_value) = required_value {
                 if final_value != required_value {
-                    eprintln!("Failed post check for final register value for {path:?}: expected {required_value}, is {final_value}");
+                    eprintln!("{path:?}: unexpected {reg}: {final_value} (expected: {required_value})");
                     found_post_check_errors = true;
                 }
             }
         }
 
         if let Some(post_gas) = post.gas {
             if expected_gas != post_gas {
-                eprintln!("Failed post check for final gas value for {path:?}: expected {post_gas}, is {expected_gas}");
+                eprintln!("{path:?}: unexpected gas: {expected_gas} (expected: {post_gas})");
                 found_post_check_errors = true;
             }
         }