Pumpkin-MC/Pumpkin · error

unexpected event

Error message

unexpected event

What it means

This panic fires in `data_from_event`, the `Event` trait implementation for `BrewingStandFuelEvent`. It only accepts `Event::BrewingStandFuelEvent(data)`; any other `Event` variant means the dispatcher delivered a mismatched payload. The library treats that as an invariant violation and panics with "unexpected event".

Solutions

1. Register the handler for `EventType::BrewingStandFuelEvent` and confirm the dispatcher keys off that type.
2. Construct events through `BrewingStandFuelEvent::data_into_event` when calling manually.
3. Align API versions across server and plugin; clean rebuild to eliminate variant mismatch.
4. Narrow first: `if let Event::BrewingStandFuelEvent(data) = event { ... }`.
5. Replace the panic with a logged error or typed `Result` for graceful failure.

Example fix

// before
match event {
    Event::BrewingStandFuelEvent(data) => data,
    _ => panic!("unexpected event"),
}
// after
match event {
    Event::BrewingStandFuelEvent(data) => data,
    _ => return None,
}

// Before dispatch
assert_eq!(event.event_type(), EventType::BrewingStandFuelEvent, "wrong event routed to BrewingStandFuel handler");

fn as_brewing_stand_fuel(event: &Event) -> Option<&BrewingStandFuelEventData> {
    match event {
        Event::BrewingStandFuelEvent(data) => Some(data),
        _ => None,
    }
}

let result = std::panic::catch_unwind(AssertUnwindSafe(|| handler.data_from_event(event)));
if result.is_err() {
    log::error!("BrewingStandFuelEvent handler received an unexpected event variant");
}

When it happens

Trigger: Calling `data_from_event` with an `Event` that is not `Event::BrewingStandFuelEvent`, such as a brewing/furnace event routed to this handler or an incorrect `EventType` registration.

Common situations: Handler registered under the wrong `EventType` in a config/registration table, custom event routing code, or `Event` enum drift after upgrading pumpkin-plugin-api so previously matched routes now fall to the `_` arm.

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

• unexpected event
• unexpected event
• unexpected event
• unexpected event
• unexpected event

AI-assisted analysis of Pumpkin-MC/Pumpkin@8d4639e25a (2026-09-09). Data as JSON: /api/errors/c4c866ad43012253. Report an issue: GitHub.

Appendix: source

Thrown at crates/pumpkin-plugin-api/src/events/inventory/brewing_stand_fuel.rs:13

use super::super::FromIntoEvent;
use crate::wit::pumpkin::plugin::event::{BrewingStandFuelEventData, Event, EventType};

/// Event triggered when brewing stand fuel is consumed or refilled.
pub struct BrewingStandFuelEvent;
impl FromIntoEvent for BrewingStandFuelEvent {
    const EVENT_TYPE: EventType = EventType::BrewingStandFuelEvent;
    type Data = BrewingStandFuelEventData;

    fn data_from_event(event: Event) -> Self::Data {
        match event {
            Event::BrewingStandFuelEvent(data) => data,
            _ => panic!("unexpected event"),
        }
    }

    fn data_into_event(data: Self::Data) -> Event {
        Event::BrewingStandFuelEvent(data)
    }
}

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