Error about run eval_coco.py

[g18tka17]

hi, author.
i meet a problem when i run python eval_coco.py --eval_data='../data/COCO/coco_minival2014.odgt' --eval_gt='../data/COCO/instances_minival2014.json' --GPU='0'

Loading and preparing results...
Traceback (most recent call last):
File "eval_coco.py", line 209, in
showbox=args.showbox)
File "eval_coco.py", line 172, in eval
cocoval(detected_json, eval_gt)
File "eval_coco.py", line 30, in cocoval
eval_dt = eval_gt.loadRes(detected_json)
File "../data/lib_coco/PythonAPI/pycocotools/coco.py", line 318, in loadRes
if 'caption' in anns[0]:
IndexError: list index out of range

I tried to find the problem，and i found that the file of /tools/eval_coco/version/coco_minival.json is empty. This means that eval_coco in the eval_coco.py file is not correctly written. Why?Looking forward to your reply. thank you