gatsbyjs/gatsby · error · Error

There is no worker with "${workerId}" id.

Error message

There is no worker with "${workerId}" id.

What it means

Worker pool sendMessage indexes this.workers by workerId-1; a falsy entry means the requested worker id is out of range or that worker already exited. It is an internal messaging guard between the Gatsby main process and its child workers.

Source

Thrown at packages/gatsby-worker/src/index.ts:482

    ...args: Array<unknown>
  ): Array<Promise<unknown>> {
    return this.workers.map(workerInfo =>
      this.scheduleWork(
        new TaskInfo({ assignedToWorker: workerInfo, functionName, args })
      )
    )
  }

  onMessage(
    listener: (msg: MessagesFromChild, workerId: number) => void
  ): void {
    this.listeners.push(listener)
  }

  sendMessage(msg: MessagesFromParent, workerId: number): void {
    const worker = this.workers[workerId - 1]
    if (!worker) {
      throw new Error(`There is no worker with "${workerId}" id.`)
    }

    const poolMsg: ParentMessageUnion = [CUSTOM_MESSAGE, ++this.counter, msg]
    worker.send(poolMsg)
  }
}

export * from "./child"

View on GitHub (pinned to e85d62f177)

Solutions

1. Verify workerId was obtained from pool.onMessage/worker creation
2. Avoid sending messages after workers have been killed or the pool tore down
3. Check for premature worker exits earlier in the log

When it happens

Trigger: Thrown at packages/gatsby-worker/src/index.ts:482 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of gatsbyjs/gatsby@e85d62f177 (2026-08-26). Data as JSON: /api/errors/97cf51934ec111ea. Report an issue: GitHub.