deepseek-ai/deepseek-harness · error · Error

PTY session ${id} is closing

Error message

PTY session ${id} is closing

What it means

Error "PTY session ${id} is closing" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/terminal/terminal/src/index.ts:245

   * Test whether an exact owner has a published session or unpublished spawn.
   * @param owner - exact live owner to inspect.
   * @returns true across the entire spawn-to-close interval, with no publication gap.
   */
  hasOwnerActivity(owner: Agent): boolean {
    return (this.pendingSpawns.get(owner)?.size ?? 0) > 0
      || [...this.sessions.values()].some(record => record.owner === owner)
  }

  /**
   * Start one exclusive interactive send.
   * @param owner - exact session owner.
   * @param id - target PTY identity.
   * @param request - explicit text, submit behavior, and cancellation.
   * @returns live operation handle for foreground await or task registration.
   */
  startSend(owner: Agent, id: TerminalSessionId, request: TerminalSendRequest): TerminalSendOperation {
    const record = this.expectOwned(owner, id)
    if (record.closing !== undefined) throw new Error(`PTY session ${id} is closing`)
    if (record.active !== undefined) throw new TerminalError(`PTY session ${id} already has an active send`, 'SEND_ACTIVE')
    const operation = record.session.startSend(request)
    record.active = operation
    void operation.done.then(
      () => { record.active = undefined },
      () => { record.active = undefined },
    )
    return operation
  }

  /**
   * Read one bounded scrollback page from an owned session.
   * @param owner - exact session owner.
   * @param id - target PTY identity.
   * @param request - optional newest-relative offset and line count.
   * @returns bounded retained text and pagination metadata.
   */
  read(owner: Agent, id: TerminalSessionId, request: TerminalReadRequest = {}): TerminalReadResult {

View on GitHub (pinned to b150a551b8)

Solutions

1. Wait for the session close to complete before further operations on it.

When it happens

Trigger: Thrown at packages/terminal/terminal/src/index.ts:245 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/1e87b09744f37606. Report an issue: GitHub.