Submit Dev Result Failed.

I participate the CNLI competion, when I submit dev result, it failed.
```
Traceback (most recent call last):
  File "/tmp/codalab/tmp3h_H9y/run/program/evaluate.py", line 22, in 
    truth = open(truth_file).readlines()
IOError: [Errno 2] No such file or directory: '/tmp/codalab/tmp3h_H9y/run/input/ref/truth.txt'
```
I find no clue to fix the error. Thank you for your time.