Pumpkin-MC/Pumpkin · critical

failed to add world resource

Error message

failed to add world resource

What it means

An `.expect("failed to add world resource")` in BlockMultiPlaceEvent::to_wasm_event. The event's world Arc must be registered as a WASM resource in PluginHostState; add_world failed, so conversion to the WASM event panics.

Solutions

1. Check that the world is still loaded when the event is dispatched
2. Inspect PluginHostState::add_world for the insertion failure cause
3. Skip WASM dispatch of events tied to unloading worlds
4. Update to a server version fixing the host-state handling

// guard before dispatching to WASM
if !world.is_loaded() || world.is_unloading() { skip_wasm_dispatch(event); }

When it happens

Trigger: Serializing a BlockMultiPlaceEvent for WASM plugins when the world reference cannot be added to the host resource table.

Common situations: Event fired while its world is being unloaded/removed; resource-table state corruption in the WASM host; version-skew between event producers and the wasm host.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• failed to add player resource
• failed to add text-component resource
• Cannot construct BlockFertilizeEvent from WASM
• unexpected event type
• Cannot construct BlockMultiPlaceEvent from WASM

AI-assisted analysis of Pumpkin-MC/Pumpkin@8d4639e25a (2026-09-09). Data as JSON: /api/errors/6b2bf6e05f048a06. Report an issue: GitHub.

Appendix: source

Thrown at crates/pumpkin/src/plugin/loader/wasm/wasm_host/wit/v0_1/events/block.rs:918

    fn from_wasm_event(event: Event, _state: &mut PluginHostState) -> Self {
        match event {
            Event::BlockFertilizeEvent(_) => {
                panic!("Cannot construct BlockFertilizeEvent from WASM")
            }
            _ => panic!("unexpected event type"),
        }
    }
}

impl ToFromWasmEvent for BlockMultiPlaceEvent {
    fn to_wasm_event(&self, state: &mut PluginHostState) -> Event {
        let player = state
            .add_player(self.player.clone())
            .expect("failed to add player resource");
        let target_world = state
            .add_world(self.world.clone())
            .expect("failed to add world resource");
        let placed_blocks = self
            .placed_blocks
            .iter()
            .map(|(pos, id)| (to_wasm_block_position(*pos), id.as_u16()))
            .collect();
        Event::BlockMultiPlaceEvent(BlockMultiPlaceEventData {
            player,
            target_world,
            placed_blocks,
            cancelled: self.cancelled,
        })
    }

    fn apply_wasm_event(&mut self, event: Event, state: &mut PluginHostState) {
        cleanup_event(&event, state);
        if let Event::BlockMultiPlaceEvent(data) = event {
            self.cancelled = data.cancelled;
        }

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