How to set local_rank in main.py?

[hieutrong512]

I used to be able to train model, but lately I can't. I made a mistake about the parameter local_rank. As follows:

I didn't edit anything in the main.py file, I tried to set os.environ['LOCAL_RANK']=0 or 1 but it wasn't works.
I run this model on Google Colab, so my GPU device is only one. But I have run it successfully before :(

Can you help me to solve this problems?