What causes "worker {worker_id} has no fleet task to restart" in Hmbown/CodeWhale?

List workers/tasks from the same ledger state to get the exact worker id spelling

worker {worker_id} has no fleet task to restart

Error message

worker {worker_id} has no fleet task to restart

What it means

FleetManager::restart_worker requires the worker to have an active task, or at least a latest (historical) task, in the rebuilt ledger state. Neither lookup succeeded, so there is nothing to restart: the worker id never received a task in any run this manager can see.

Source

Thrown at crates/tui/src/fleet/manager.rs:1029

            &task.entry.task_id,
            Some(worker_id),
            &timestamp(),
            Some("operator"),
            Some("operator"),
        )?;
        if !cancelled {
            bail!("worker {worker_id} no longer has that running fleet task");
        }
        self.refresh_run_status(&task.entry.run_id)?;
        self.inspect_worker(worker_id)
    }

    pub fn restart_worker(&self, worker_id: &str) -> Result<FleetRestartReport> {
        let state = self.ledger.rebuild_state()?;
        let Some(task) = active_task_for_worker(&state, worker_id)
            .or_else(|| latest_task_for_worker(&state, worker_id))
        else {
            bail!("worker {worker_id} has no fleet task to restart");
        };
        let run = state
            .runs
            .get(&task.entry.run_id.0)
            .ok_or_else(|| anyhow!("fleet run {} does not exist", task.entry.run_id.0))?;
        let max_workers = run
            .max_workers
            .unwrap_or_else(|| run.worker_specs.len().max(1))
            .clamp(1, 128);
        let mut coordination_guard = match &self.sub_agent_manager {
            Some(manager) => {
                let Ok(guard) = manager.try_write() else {
                    bail!("Fleet worker {worker_id} coordination state is busy; retry restart");
                };
                Some(guard)
            }
            None => None,
        };

View on GitHub (pinned to 0c42157ee5)

Solutions

List workers/tasks from the same ledger state to get the exact worker id spelling
Confirm you are operating on the correct run and state directory
If the worker should have history, check that its task events were appended to the ledger and were not lost
Use a launch/assign API to give the worker a task before restarting it

Defensive patterns

Strategy: validation

Validate before calling

// before restarting, confirm the worker appears in current state
let state = manager.ledger_state()?; // or expose a list/inspect API
let known = manager.inspect_worker(&worker_id).is_ok();
assert!(known, "worker id unknown to this fleet state");

Try / catch

match manager.restart_worker(&worker_id) {
    Ok(report) => Ok(report),
    Err(err) if err.to_string().contains("no fleet task to restart") => {
        eprintln!("worker {worker_id} has no task history; check the id and run");
        Err(err)
    }
    Err(err) => Err(err),
}

Prevention

Copy worker ids from a live listing, never from scrollback
Validate that worker ids come from the same run/state directory you are managing

When it happens

Trigger: Calling restart_worker with a worker id that has no tasks in the rebuilt ledger: a typo'd id, an id from a different run directory, or a worker whose events were never written.

Common situations: Copy-pasting a worker id from an old run; referencing a worker by its spec id while the ledger keys by lease-assigned id; pointing CODEWHALE state at the wrong directory so the ledger rebuilds without that worker's history.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

AI-assisted analysis of Hmbown/CodeWhale@0c42157ee5 (2026-08-20). Data as JSON: /api/errors/ef97ac3a5ceccfb5. Report an issue: GitHub.