GPUOptions' object has no attribute 'allocator_type'

[air2c]

Mode : train

Preparing data in working_dir/
Tokenizing data in data/train.enc
tokenizing line 100000
Tokenizing data in data/train.dec
tokenizing line 100000
Tokenizing data in data/test.enc
Traceback (most recent call last):
File "execute.py", line 319, in
train()
File "execute.py", line 132, in train
config.gpu_options.allocator_type = 'BFC'
AttributeError: 'GPUOptions' object has no attribute 'allocator_type'

How should I solve it?