Added traceback to save voucher to better understand why an error occurs.

barker/barker/routers/voucher/save.py

@@ -1,3 +1,4 @@
+import traceback
 import uuid
 
 from datetime import datetime, timedelta
@@ -61,6 +62,7 @@ def save(
             if item.voucher_type != VoucherType.KOT:
                 print_bill(voucher_id, db)
     except SQLAlchemyError as e:
+        traceback.print_exc()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             detail=str(e),