bug fix

core/trainers/single_trainer.py

@@ -248,8 +248,15 @@ class SingleTrainer(TranspileTrainer):
         _exe_strategy = fluid.ExecutionStrategy()
 
         # 0: kCoeffNumDevice; 1: One; 2: Customized
-        _build_strategy.gradient_scale_strategy = model_dict.get(
-            "gradient_scale_strategy", 0)
+        _gradient_scale_strategy = model_dict.get("gradient_scale_strategy", 0)
+        if _gradient_scale_strategy == 0:
+            gradient_scale_strategy = fluid.BuildStrategy.GradientScaleStrategy.CoeffNumDevice
+        elif _gradient_scale_strategy == 1:
+            gradient_scale_strategy = fluid.BuildStrategy.GradientScaleStrategy.One
+        elif _gradient_scale_strategy == 2:
+            gradient_scale_strategy = fluid.BuildStrategy.GradientScaleStrategy.Customized
+        _build_strategy.gradient_scale_strategy = gradient_scale_strategy
+
         if "thread_num" in model_dict and model_dict["thread_num"] > 1:
             _build_strategy.reduce_strategy = fluid.BuildStrategy.ReduceStrategy.Reduce
             _exe_strategy.num_threads = model_dict["thread_num"]