ATH-MaaS/Pixelle-Video · error · HTTPException

str(e)

Error message

str(e)

What it means

GET /tasks converts any exception from task_manager.list_tasks() into HTTP 500 with str(e) as detail. The task listing/registry itself failed — for example corrupted in-memory task state, an invalid status filter path, or an internal error in the task manager — after query validation already passed.

Source

Thrown at api/routers/tasks.py:49

    limit: int = Query(100, ge=1, le=1000, description="Maximum number of tasks")
):
    """
    List tasks
    
    Retrieve list of tasks with optional filtering.
    
    - **status**: Optional filter by status (pending/running/completed/failed/cancelled)
    - **limit**: Maximum number of tasks to return (default 100)
    
    Returns list of tasks sorted by creation time (newest first).
    """
    try:
        tasks = task_manager.list_tasks(status=status, limit=limit)
        return tasks
        
    except Exception as e:
        logger.error(f"List tasks error: {e}")
        raise HTTPException(status_code=500, detail=str(e))


@router.get("/{task_id}", response_model=Task)
async def get_task(task_id: str):
    """
    Get task details
    
    Retrieve detailed information about a specific task.
    
    - **task_id**: Task ID
    
    Returns task details including status, progress, and result (if completed).
    """
    try:
        task = task_manager.get_task(task_id)
        
        if not task:
            raise HTTPException(status_code=404, detail=f"Task {task_id} not found")

View on GitHub (pinned to 848b054e4f)

Solutions

  1. Check server logs for 'List tasks error:' to find the root cause
  2. Retry the request — transient state issues may resolve
  3. Call without the status/limit filters to isolate whether filtering triggers the failure
  4. Restart the service if the in-memory task registry is corrupted
  5. Server-side: return a sanitized message and log the full stack trace

Example fix

// before
except Exception as e:
    logger.error(f"List tasks error: {e}")
    raise HTTPException(status_code=500, detail=str(e))
// after
except Exception:
    logger.exception("List tasks error")
    raise HTTPException(status_code=500, detail="Unable to list tasks")
Defensive patterns

Strategy: retry

Validate before calling

// validate query params before calling
const validStatus = ['pending','running','completed','failed','cancelled'];
if (status && !validStatus.includes(status)) throw new Error(`invalid status: ${status}`);
if (limit < 1 || limit > 1000) throw new Error('limit must be 1-1000');

Type guard

function isTaskList(r) { return Array.isArray(r) && r.every(t => typeof t.id === 'string' && typeof t.status === 'string'); }

Try / catch

async function listTasks(params, attempts = 3) {
  try {
    const res = await fetch('/tasks?' + new URLSearchParams(params));
    if (!res.ok) throw Object.assign(new Error('list tasks failed'), {status: res.status});
    return await res.json();
  } catch (err) {
    if (err.status === 500 && attempts > 1) {
      await sleep(500);
      return listTasks(params, attempts - 1);
    }
    throw err;
  }
}

Prevention

When it happens

Trigger: GET /tasks?status=...&limit=... when task_manager.list_tasks throws: internal state error, unexpected exception while sorting/filtering stored tasks, or serialization of a malformed Task record.

Common situations: Task manager registry in a bad state after a restart or memory pressure; a stored Task record missing required fields failing response serialization; bug in a new task-manager version.

Related errors

AI-assisted analysis of ATH-MaaS/Pixelle-Video@848b054e4f (2026-08-30). Data as JSON: /api/errors/de4e2faf79b2fb4c. Report an issue: GitHub.