nautechsystems/nautilus_trader · error

Order {client_order_id} not found

Error message

Order {client_order_id} not found

What it means

This panic occurs in the cache's bulk order fetch loop: for each id in client_order_ids it expects self.orders to contain an entry and panics otherwise via unwrap_or_else. The method is designed for callers that already hold guaranteed-valid order ids, so a missing id is treated as a programmer error.

Source

Thrown at crates/common/src/cache/mod.rs:5904

    }

    /// Retrieves orders corresponding to the `client_order_ids`, optionally filtering by `side`.
    ///
    /// # Panics
    ///
    /// Panics if any `client_order_id` in the set is not found in the cache.
    fn get_orders_for_ids(
        &self,
        client_order_ids: &AHashSet<ClientOrderId>,
        side: Option<OrderSide>,
    ) -> Vec<OrderRef<'_>> {
        let mut orders = Vec::new();

        for client_order_id in client_order_ids {
            let order_cell = self
                .orders
                .get(client_order_id)
                .unwrap_or_else(|| panic!("Order {client_order_id} not found"));
            let order = OrderRef::new(order_cell.borrow());

            if side.is_none_or(|side| side == order.order_side()) {
                orders.push(order);
            }
        }

        // Sort so callers receive a deterministic Vec across runs; the
        // underlying client_order_ids set is AHash-backed.
        orders.sort_by_key(|o| o.client_order_id());
        orders
    }

    /// Retrieves positions corresponding to the `position_ids`, optionally filtering by `side`.
    ///
    /// Each [`PositionRef`] in the returned vector borrows its underlying cell; mutating any of
    /// those positions while the vector is alive will panic at runtime. Drop the vector before
    /// issuing writes.

View on GitHub (pinned to 18893faf8b)

Solutions

1. Confirm every id in client_order_ids was created in this run and is still in the cache
2. Filter the id list against cache presence (e.g. a contains/order lookup returning Option) before the bulk fetch
3. Check for cache eviction/cleanup that removed orders referenced later
4. Log the offending client_order_id and verify it against the source that produced it

Example fix

// before
let ids: Vec<Ustr> = external_report_ids();
let orders = cache.orders(&ids, None);
// after
let ids: Vec<Ustr> = external_report_ids()
    .into_iter()
    .filter(|id| cache.order(id).is_some())
    .collect();
let orders = cache.orders(&ids, None);

let known: Vec<&Ustr> = client_order_ids
    .iter()
    .filter(|id| cache.order(id).is_some())
    .collect();

When it happens

Trigger: Calling the bulk order accessor with a client_order_id that was never created, that was purged from the cache, or that belongs to a different venue/backtest run.

Common situations: Reusing client order ids from a previous session or persisted log whose orders were evicted; a typo in the id; building an id list from external state (fills, orders.csv) not synchronized with the in-memory cache.

Understand the failure class

Background: Record Not Found Errors: "not found", RecordNotFound, and "was not found" — what they mean and how to fix them — this error's family across 28 libraries.

Related errors

• Position {position_id} not found
• Order for {} not found to determine position ID
• Order {client_order_id} not found in cache.
• venue-leg quantity calculation validated cumulative fills
• DataActor must be registered before accessing cache

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/23eeb93ca7faa3f9. Report an issue: GitHub.