Error Encountered While Running 'run_generation.py' Script

I am facing an issue when attempting to run the 'run_generation.py' script from the 'unlimiformer/src' directory. This script is crucial for my work with **Unlimiformer on Google Colab**, and I need assistance in resolving the problem.

When executing the following command:
```
python src/run_generation.py --model_type llama --model_name_or_path meta-llama/Llama-2-13b-chat-hf \
--prefix "[INST] <>\n You are a helpful assistant. Answer with detailed responses according to the entire instruction or question. \n<>\n\n Summarize the following book: " \
--prompt example_inputs/harry_potter_full.txt \
--suffix " [/INST]" --test_unlimiformer --fp16 --length 200 --layer_begin 16 \
--index_devices 1 --datastore_device 1
```

the script runs on Google Colab, but it abruptly terminates with the following error message:

```
10/05/2023 11:16:12 - WARNING - __main__ - device: cuda, n_gpu: 1, 16-bits training: True
Using pad_token, but it is not set yet.
^C
```

The script utilizes the 'cuda' device, and I have one GPU ('n_gpu: 1') available for the process.
I am enabling 16-bits training with the '--fp16' flag.
The script also specifies various parameters, including 'length,' 'layer_begin,' 'index_devices,' and 'datastore_device.'
The issue arises when running the script but does not provide a clear indication of the problem's root cause.

The error occurs in run_generation.py when using the Llama model. Start by examining the script in src/run_generation.py, focusing on the tokenizer setup and pad_token configuration. Check the model loading and initialization steps, and run a minimal test to see if the pad_token warning is the cause of termination. Look for any existing tests or similar issues in the repository.

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