fix ci bug

python/paddle/fluid/tests/unittests/test_cross_entropy_loss.py

@@ -20,6 +20,7 @@ import numpy as np
 import unittest
 from test_softmax_op import stable_softmax
 from test_softmax_with_cross_entropy_op import cross_entropy
+from paddle.fluid import Program, program_guard
 
 
 def stable_softmax(x):

python/paddle/nn/functional/loss.py

@@ -1411,7 +1411,7 @@ def cross_entropy(input,
                 out = core.ops.elementwise_mul(out, weight_gather_reshape)
 
             else:
-                for label_val in label:
+                for label_val in label.flatten():
                     if label_val < 0 or label_val >= input.shape[-1]:
                         raise ValueError(
                             'Expected 0 <= label_value < class_dimension({}), but got label_value {}'.