@ -486,7 +486,7 @@ def append_backward(loss, parameter_list=None, no_grad_set=None,
params_and_grads = []
for param in parameters:
if param not in grad_info_map:
raise ValueError("param %s is not in map" % param)
continue
grad_info = grad_info_map[param]
grad_block = grad_info[1]
if not grad_block.has_var(grad_info[0]):