Hmbown/CodeWhale · error · anyhow::Error

Thread engine not loaded

Error message

Thread engine not loaded

What it means

Inside the start-turn critical section, the thread id had no entry in the active engines map — the engine was expected to be loaded (ensure_engine_loaded ran earlier) but is not registered. Effectively an internal invariant failure, typically triggered by concurrent teardown/eviction of the engine between load and claim.

Source

Thrown at crates/tui/src/runtime_threads.rs:6112

            provenance: input_source.provenance(),
        };

        // Reserve mailbox capacity before claiming or persisting anything.
        // If the caller is cancelled while capacity is unavailable, no
        // durable or in-memory turn state has changed.
        let permit = engine
            .tx_op
            .clone()
            .reserve_owned()
            .await
            .map_err(|_| anyhow!("Failed to start turn: engine operation channel closed"))?;

        let acceptance_rx = {
            // Lock order is active -> thread_mutation. Neither guard crosses
            // an await, and spawning the owned lifecycle task is synchronous.
            let mut active = self.active.lock().await;
            let Some(state) = active.engines.get_mut(thread_id) else {
                bail!("Thread engine not loaded");
            };
            if state.active_turn.is_some() {
                bail!("Thread already has an active turn");
            }
            let _thread_mutation = self.store.thread_mutation.lock();
            let mut current_thread = self.store.load_thread(thread_id)?;
            if !thread_execution_state_matches(&thread, &current_thread) {
                bail!("Thread execution settings changed while preparing the turn; retry");
            }
            let previous_active_route = (state.route_identity.clone(), state.route_model.clone());
            state.active_turn = Some(ActiveTurnState {
                turn_id: turn_id.clone(),
                interrupt_requested: false,
                compaction_id: None,
            });
            state.route_identity = provider_identity;
            state.route_model.clone_from(&model);

View on GitHub (pinned to 0c42157ee5)

Solutions

1. Retry the turn start so the engine reloads
2. If persistent, check for concurrent thread teardown or eviction

When it happens

Trigger: Thrown at crates/tui/src/runtime_threads.rs:6112 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/9469225b365a790c. Report an issue: GitHub.