raise error when checkpoint not exist (PaddlePaddle#2719)

Author: heavengate

PaddleCV/PaddleDetection/ppdet/utils/checkpoint.py

@@ -52,7 +52,8 @@ def load_pretrain(exe, prog, path):
         path = get_weights_path(path)
 
     if not os.path.exists(path):
-        logger.info('Model path {} does not exists.'.format(path))
+        raise ValueError("Model pretrain path {} does not "
+                         "exists.".format(path))
 
     logger.info('Loading pretrained model from {}...'.format(path))
 
@@ -77,7 +78,8 @@ def load_checkpoint(exe, prog, path):
         path = get_weights_path(path)
 
     if not os.path.exists(path):
-        logger.info('Model path {} does not exists.'.format(path))
+        raise ValueError("Model checkpoint path {} does not "
+                         "exists.".format(path))
 
     logger.info('Loading checkpoint from {}...'.format(path))
     fluid.io.load_persistables(exe, path, prog)
@@ -127,6 +129,9 @@ def load_and_fusebn(exe, prog, path):
     if is_url(path):
         path = get_weights_path(path)
 
+    if not os.path.exists(path):
+        raise ValueError("Model path {} does not exists.".format(path))
+
     def _if_exist(var):
         b = os.path.exists(os.path.join(path, var.name))
         if b: