keras-team/keras · error · ValueError

Cannot create sharding when device mesh is not set for Tenso

Error message

Cannot create sharding when device mesh is not set for TensorLayout.

What it means

Error "Cannot create sharding when device mesh is not set for TensorLayout." thrown in keras-team/keras.

Source

Thrown at keras/src/backend/jax/distribution_lib.py:216

        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):
    """Convert the TensorLayout to JAX backend specific Sharding.

    Args:
        tensor_layout: TensorLayout instance to convert.

    Returns:
        A `jax.sharding.NamedSharding` instance.
    """
    if tensor_layout.device_mesh is None:
        raise ValueError(
            "Cannot create sharding when device mesh is not set "
            "for TensorLayout."
        )
    partition_spec = jax.sharding.PartitionSpec(*tensor_layout.axes)
    jax_mesh = tensor_layout.device_mesh.backend_mesh
    return jax.sharding.NamedSharding(jax_mesh, partition_spec)

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/jax/distribution_lib.py:216 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/ea76d93517312113. Report an issue: GitHub.