deepseek-ai/deepseek-harness · error

workflow-worker-thread: postMessage failed: ${renderThrown(e

Error message

workflow-worker-thread: postMessage failed: ${renderThrown(error)}

What it means

Error "workflow-worker-thread: postMessage failed: ${renderThrown(error)}" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/workflow/workflow-worker-thread/src/host.ts:264

    })().then(
      () => { claimed.resolve(undefined) },
      /* v8 ignore next -- result/quiescence never reject and Worker.terminate is the only external promise */
      (error: unknown) => { claimed.reject(error) },
    )
    return this.disposed
  }

  /** Post one message to the worker (payload looked up from the tag's map entry), tolerating a thread that is already gone. */
  private post<T extends HostToWorkerType>(type: T, payload: HostToWorkerPayloads[T]): void {
    if (this.workerGone || this.workerDeathObserved) return
    try {
      this.worker.postMessage({ type, ...payload })
    } catch (error: unknown) {
      // Only a teardown race can land here (every engine message is JSON
      // data, so serialization cannot fail); there is nothing left to
      // deliver to — log and move on.
      /* v8 ignore next -- postMessage teardown race (a throw between exit and its event): not constructible in-process */
      this.ctx.logger.warn(`workflow-worker-thread: postMessage failed: ${renderThrown(error)}`)
    }
  }

  private onMessage(message: WorkerToHostMessage): void {
    // Node may emit `error`, then deliver an already-queued `message`, then
    // emit `exit`. The first death signal is the host's logical delivery
    // barrier: nothing arriving afterward may create a child, narrate after
    // workflow/end, or compete with the chosen outcome.
    if (this.workerDeathObserved) return
    switch (message.type) {
      case WorkerToHostType.Ready:
        this.post(HostToWorkerType.Go, {})
        break
      case WorkerToHostType.Phase:
        // Post-cancel narration is suppressed host-side: worker-side the
        // hooks throw once the cancel message is PROCESSED, but narration
        // already in flight (or emitted while the cancel crossed the
        // boundary) must not reach observers — nothing is emitted after

View on GitHub (pinned to b150a551b8)

Solutions

1. Verify the worker thread is still running; recreate the workflow worker if it exited or its port closed.

When it happens

Trigger: Thrown at packages/workflow/workflow-worker-thread/src/host.ts:264 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/b616ee4554dcca10. Report an issue: GitHub.