keras-team/keras · error · ValueError

Unsupported reduction: {reduction}

Error message

Unsupported reduction: {reduction}

What it means

Error "Unsupported reduction: {reduction}" thrown in keras-team/keras.

Source

Thrown at keras/src/backend/jax/core.py:596

def scatter_update(inputs, indices, updates, reduction=None):
    inputs = convert_to_tensor(inputs)
    indices = jnp.array(indices)
    indices = jnp.transpose(indices)
    idx = tuple(indices)
    if reduction is None:
        return inputs.at[idx].set(updates)
    elif reduction == "add":
        return inputs.at[idx].add(updates)
    elif reduction == "max":
        return inputs.at[idx].max(updates)
    elif reduction == "min":
        return inputs.at[idx].min(updates)
    elif reduction == "mul":
        return inputs.at[idx].multiply(updates)
    else:
        raise ValueError(f"Unsupported reduction: {reduction}")


def slice(inputs, start_indices, shape):
    # If shape[i] is -1, all remaining elements in dimension i are included in
    # the slice.
    final_shape = tuple(
        inputs.shape[i] - start_indices[i] if s == -1 else s
        for i, s in enumerate(shape)
    )
    return jax.lax.dynamic_slice(inputs, start_indices, final_shape)


def slice_update(inputs, start_indices, updates):
    return jax.lax.dynamic_update_slice(inputs, updates, start_indices)


def switch(index, branches, *operands):
    return jax.lax.switch(index, branches, *operands)

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/backend/jax/core.py:596 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/a15960cb10bbab82. Report an issue: GitHub.