keras-team/keras · error · ValueError

Device not found: {device_name}

Error message

Device not found: {device_name}

What it means

Error "Device not found: {device_name}" thrown in keras-team/keras.

Source

Thrown at keras/src/backend/jax/distribution_lib.py:188

def process_id():
    """Return the current process ID for the distribution setting."""
    return jax.process_index()


def _to_backend_device(device_name):
    if isinstance(device_name, jax.Device):
        return device_name
    device_name = str(device_name)
    if ":" not in device_name:
        device_type, device_id = device_name, 0
    else:
        device_type, device_id = device_name.split(":")

    devices = jax.devices(backend=device_type)
    for device in devices:
        if device.platform == device_type and device.id == int(device_id):
            return device
    raise ValueError(f"Device not found: {device_name}")


def _to_backend_mesh(device_mesh):
    """Convert the DeviceMesh to JAX backend specific Mesh.

    Args:
        device_mesh: DeviceMesh instance to convert.

    Returns:
        A `jax.sharding.Mesh` instance.
    """
    shape = device_mesh.devices.shape
    devices = [_to_backend_device(d) for d in device_mesh.devices.flatten()]
    devices = np.array(devices).reshape(shape)
    return jax.sharding.Mesh(devices, device_mesh.axis_names)


def _to_backend_layout(tensor_layout):

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/jax/distribution_lib.py:188 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/49401833eccf8a99. Report an issue: GitHub.