Bus error when running single string as input on MacOS

[Saibo-creator]

This bug is very wired....

I can not reproduce it on linux machine but only on my local macbook....

Bascially, with a batch size of 1, I get this wired error

    input_ids = tokenizer(
        [prefix1], add_special_tokens=False, return_tensors="pt", padding=True
    )["input_ids"] # 2415 bus error  python examples/generate_json.py

->
[1] 2415 bus error python examples/generate_json.py

But with batch size = 2, it disappears...

    input_ids = tokenizer(
        [prefix1, prefix1], add_special_tokens=False, return_tensors="pt", padding=True
    )["input_ids"] 

import torch
from transformers import AutoModelForCausalLM, AutoTokenizer
from transformers_cfg.grammar_utils import IncrementalGrammarConstraint
from transformers_cfg.generation.logits_process import GrammarConstrainedLogitsProcessor


if __name__ == "__main__":

    model_id = "gpt2"

    # Load model and tokenizer
    tokenizer = AutoTokenizer.from_pretrained(model_id)
    tokenizer.pad_token = tokenizer.eos_token

    model = AutoModelForCausalLM.from_pretrained(model_id)
    model.generation_config.pad_token_id = model.generation_config.eos_token_id

    # Load grammar
    with open("examples/grammars/json.ebnf", "r") as file:
        grammar_str = file.read()
    grammar = IncrementalGrammarConstraint(grammar_str, "root", tokenizer)
    grammar_processor = GrammarConstrainedLogitsProcessor(grammar)

    # Generate
    prefix1 = "This is a valid json string for http request:"
    prefix2 = "This is a valid json string for shopping cart:"
    input_ids = tokenizer(
        [prefix1], add_special_tokens=False, return_tensors="pt", padding=True
    )["input_ids"] # 2415 bus error  python examples/generate_json.py

    # input_ids = tokenizer(
    #     [prefix1, prefix2], add_special_tokens=False, return_tensors="pt", padding=True
    # )["input_ids"] # this works fine

    output = model.generate(
        input_ids,
        do_sample=False,
        max_new_tokens=60,
        logits_processor=[grammar_processor],
        repetition_penalty=1.1,
        num_return_sequences=1,
    )
    # decode output
    generations = tokenizer.batch_decode(output, skip_special_tokens=True)
    print(generations)

    """
    'This is a valid json string for http request:{ "request": { "method": "GET", "headers": [], "content": "Content","type": "application" }}
    'This is a valid json string for shopping cart:This is a valid json string for shopping cart:{ "name": "MyCart", "price": 0, "value": 1 }
    """