diff --git a/tiramisu/autolib.py b/tiramisu/autolib.py
index 8b6de4e..54d165b 100644
--- a/tiramisu/autolib.py
+++ b/tiramisu/autolib.py
@@ -177,7 +177,7 @@ def carry_out_calculation(option, context, callback, callback_params,
                             else:
                                 raise err
                         else:
-                            raise err
+                            raise value
                     # convert to list, not modifie this multi
                     if value.__class__.__name__ == 'Multi':
                         value = list(value)
@@ -228,7 +228,7 @@ def carry_out_calculation(option, context, callback, callback_params,
         if not option.impl_is_optiondescription() and callback_params != {} and isinstance(ret, list) and \
                 option.impl_is_master_slaves('slave'):
             raise SlaveError(_("callback cannot return a list for a "
-                               "slave option ({0})").format(path))
+                               "slave option ({0})").format(option.impl_getname()))
         return ret