bytecode cache issue

app.py

@@ -163,7 +163,16 @@ def evaluate_submission(file_obj, debug=False):
         print(f"\n{'='*60}")
         print(f"EVALUATING: {file_path}")
         print(f"{'='*60}\n")
-                
+        
+        # Clear bytecode cache to prevent "unmarshallable object" errors
+        from pathlib import Path
+        import shutil
+        pycache = Path(file_path).parent / "__pycache__"
+        if pycache.exists():
+            shutil.rmtree(pycache, ignore_errors=True)
+
+        print("### Cleared bytecode cache.")
+
         # Import with a unique module name each time
         module_name = f"student_module_{int(time.time() * 1000000)}"
         spec = importlib.util.spec_from_file_location(module_name, file_path)