Pumpkin-MC/Pumpkin · critical

failed to add player resource

Error message

failed to add player resource

What it means

An `.expect("failed to add player resource")` in BlockMultiPlaceEvent::to_wasm_event. When converting the native event to its WASM representation, the player's Arc reference must be registered in PluginHostState's resource table; add_player returned None/Err, so the conversion aborts.

Solutions

1. Ensure the player entity is still alive/valid when the event fires
2. Inspect PluginHostState::add_player for why insertion failed
3. Update server if this occurs during normal gameplay (likely a host-state bug)
4. Avoid dispatching this event to WASM plugins for despawned players

// guard before dispatching to WASM
if !player.is_alive() || player.is_removed() { skip_wasm_dispatch(event); }

When it happens

Trigger: Serializing a BlockMultiPlaceEvent for a WASM plugin when the player resource cannot be inserted into the host state table (e.g. player already freed or table in a bad state).

Common situations: Firing a multi-block-place event during teardown or for an already-removed player; resource-table exhaustion or state bug in 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 world 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/7d570939ed853098. Report an issue: GitHub.

Appendix: source

Thrown at crates/pumpkin/src/plugin/loader/wasm/wasm_host/wit/v0_1/events/block.rs:915

            self.cancelled = data.cancelled;
        }
    }

    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);

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