Created by: hexmiao

环境信息：PaddlePaddle-1.4.0， CPU单机训练， Mac OS 10.10 Python 3.5 当训练完一个轮次，调用 fluid.io.save_inference_model 方法时，报以下错误：

File "/Users/hex/paddle/lib/python3.5/site-packages/paddle/fluid/io.py", line 1000, in save_inference_model prepend_feed_ops(main_program, feeded_var_names) File "/Users/hex/paddle/lib/python3.5/site-packages/paddle/fluid/io.py", line 840, in prepend_feed_ops out = global_block.var(name) File "/Users/hex/paddle/lib/python3.5/site-packages/paddle/fluid/framework.py", line 1448, in var raise ValueError("var %s not in this block" % name) ValueError: var input not in this block