huggingface/transformers · error · AssertionError

The model must use a 'static' caching implementation to be e

Error message

The model must use a 'static' caching implementation to be exported with static caching. Please set `generation_config.cache_implementation='static'`.

What it means

Error "The model must use a 'static' caching implementation to be exported with static caching. Please set `generation_config.cache_implementation='static'`." thrown in huggingface/transformers.

Source

Thrown at src/transformers/integrations/executorch.py:520

        """
        super().__init__()

        config = model.config.get_text_config()
        generation_config = model.generation_config

        # Sanity checks
        if generation_config is None:
            raise AssertionError(
                "The model must have a generation config to be exported with static caching. "
                "Please set `generation_config` in `model`."
            )
        if not generation_config.use_cache:
            raise AssertionError(
                "The model must have caching enabled to be exported with static caching. "
                "Please set `generation_config.use_cache=True`."
            )
        if generation_config.cache_implementation != "static":
            raise AssertionError(
                "The model must use a 'static' caching implementation to be exported with static caching. "
                "Please set `generation_config.cache_implementation='static'`."
            )

        cache_config = {} if generation_config.cache_config is None else generation_config.cache_config

        # Ensure batch_size and max_cache_len are set
        if batch_size is None:
            batch_size = cache_config.get("batch_size", None)
            if batch_size is None:
                raise ValueError("batch_size must be provided, either as an argument or in cache_config.")
        if max_cache_len is None:
            max_cache_len = cache_config.get("max_cache_len", None)
            if max_cache_len is None:
                raise ValueError("max_cache_len must be provided, either as an argument or in cache_config.")
        # Infer device if not provided
        if device is None:
            device = cache_config.get("device", model.device)

View on GitHub (pinned to a597f97485)

Solutions

1. Set `generation_config.cache_implementation='static'` before export.

When it happens

Trigger: Raised in ExecuTorch static-cache export when cache_implementation is not 'static'.

Common situations: Exporting to ExecuTorch with generation_config.cache_implementation left as dynamic or another value.

AI-assisted analysis of huggingface/transformers@a597f97485 (2026-08-14). Data as JSON: /api/errors/f7d70e1eb245139b. Report an issue: GitHub.