DioxusLabs/dioxus · error

scope output

Error message

scope output

What it means

Internal invariant while pushing a component dynamic node's root nodes: the component scope was expected to have mounted output. A component dynamic node without a rendered root means the component never rendered successfully.

Source

Thrown at packages/core/src/diff/iterator.rs:631

        dom: &VirtualDom,
        to: &mut dyn WriteMutations,
    ) -> usize {
        match &self.vnode().dynamic_node_values()[idx] {
            DynamicNode::Fragment(nodes) => {
                let mounts = dom.mounted_fragment_children_exact(mount, idx, nodes.len());
                nodes
                    .iter()
                    .zip(mounts)
                    .map(|(node, mount)| {
                        crate::MountedVNode::new(node, mount).push_all_root_nodes(dom, to)
                    })
                    .sum()
            }
            DynamicNode::Component(_) => dom
                .get_scope(dom.unchecked_mounted_dynamic_component_scope(mount, idx))
                .unwrap()
                .try_mounted_root_node()
                .expect("scope output")
                .push_all_root_nodes(dom, to),
            DynamicNode::Text(_) => {
                if dom.mount_target_id(mount) == target_id {
                    let id = dom
                        .unchecked_mounted_dynamic_text_node(mount, idx)
                        .element_id();
                    push_live_root(to, id)
                } else {
                    0
                }
            }
        }
    }
}

fn push_live_root(to: &mut dyn WriteMutations, id: ElementId) -> usize {
    // Callers (`push_all_root_nodes`) only reach this with `id` values just
    // read from a root anchor/dynamic text slot for a vnode whose mount target already matches

View on GitHub (pinned to 24f6a829df)

Solutions

1. This is an internal invariant about scope output during diffing. Report it with a minimal reproduction to the Dioxus issue tracker.

When it happens

Trigger: Thrown at packages/core/src/diff/iterator.rs:631 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of DioxusLabs/dioxus@24f6a829df (2026-08-23). Data as JSON: /api/errors/823cf0248d200f58. Report an issue: GitHub.