jax-ml/jax · error · TypeError

Default value must be of type int, got {default} of type {ge

Error message

Default value must be of type int, got {default} of type {getattr(type(default), '__name__', type(default))}

What it means

int_state requires the `default` for an integer config flag to be an int (note: bool is a subclass of int and would pass; floats and strings do not). Non-int defaults raise this TypeError at flag definition.

Source

Thrown at jax/_src/config.py:703

    validator: Callable[[Any], None] | None = None,
) -> State[int]:
  """Set up thread-local state and return a contextmanager for managing it.

  See docstring for ``bool_state``.

  Args:
    name: string, converted to lowercase to define the name of the config
      option (and absl flag). It is converted to uppercase to define the
      corresponding shell environment variable.
    default: optional int, default value.
    help: string, used to populate the flag help information as well as the
      docstring of the returned context manager.

  Returns:
    A contextmanager to control the thread-local state value.
  """
  if not isinstance(default, int):
    raise TypeError(f"Default value must be of type int, got {default} "
                    f"of type {getattr(type(default), '__name__', type(default))}")
  name = name.lower()
  default_env = os.getenv(name.upper())
  if default_env is not None:
    try:
      default = int(default_env)
    except ValueError:
      raise ValueError(f"Invalid value \"{default_env}\" for JAX flag {name}")
  config._contextmanager_flags.add(name)

  def parser(new_val):
    if new_val is not None and not isinstance(new_val, int):
      raise ValueError(f'new int config value must be None or of type int, '
                       f'got {new_val} of type {type(new_val)}')
    if new_val is not None and validator is not None:
      validator(new_val)
    return new_val

View on GitHub (pinned to 1e1c6a8fc0)

Solutions

1. Pass a literal int: default=10
2. Convert env/file values: default=int(raw_value) before calling int_state

Example fix

// before
config.int_state('my_flag', default='10')
// after
config.int_state('my_flag', default=10)

assert isinstance(default, int) and not isinstance(default, bool)

def is_plain_int(v) -> bool:
    return isinstance(v, int) and not isinstance(v, bool)

When it happens

Trigger: Calling config.int_state('my_flag', default='10') or default=10.5.

Common situations: Defining size/limit flags (cache sizes, retry counts) where the default comes from a string config file and is not converted to int.

Related errors

• bool() not supported for instances of type '{0}' (did you me
• Default value must be of type bool, got {default} of type {g
• Default value must be of type str, got {default} of type {ge
• Default value must be of type str or None, got {default} of
• Default value must be of type {enum_class}, got {default} of

AI-assisted analysis of jax-ml/jax@1e1c6a8fc0 (2026-08-27). Data as JSON: /api/errors/9b33e35b47c4c631. Report an issue: GitHub.