deepseek-ai/deepseek-harness · error

acp: continuable subagent teardown failed: ${String(error)}

Error message

acp: continuable subagent teardown failed: ${String(error)}

What it means

Error "acp: continuable subagent teardown failed: ${String(error)}" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/acp/acp/src/index.ts:490

      // available. session/event enqueues output synchronously before idle.
      await Promise.all(records.map(async (record) => {
        await record.inflight?.admissionDone
        await record.agent.whenIdle()
        await record.outputTail
      }))
      // Continuable subagents outlive the turn that started them, and their
      // Activations own descendant teardown. Drain only these sessions' forests
      // child-first BEFORE disposing the top-level agents, so no descendant is
      // left holding a runtime its owner already released and another frontend
      // sharing this Context remains live.
      // Read the one teardown method structurally: the bridge needs no other
      // part of the subagent seam, so it does not depend on that package.
      const subagents = ctx.get('subagents') as ContinuableDrain | undefined
      if (subagents !== undefined) {
        try {
          await subagents.drainContinuableDescendants(records.map(record => record.agent))
        } catch (error: unknown) {
          logger.warn(`acp: continuable subagent teardown failed: ${String(error)}`)
        }
      }
      const disposals = await Promise.allSettled(records.map(record => record.dispose()))
      const failures: unknown[] = []
      for (const result of disposals) {
        if (result.status === 'rejected') failures.push(result.reason as unknown)
      }
      if (failures.length > 0) {
        // The production consumer logs this AggregateError through `String`,
        // which renders only its message. Embed every per-session diagnostic,
        // including nested causes and aggregate members, in that message.
        const detail = failures.map(failure => errorChain(failure)).join('; ')
        throw new AggregateError(
          failures,
          `ACP agent teardown failed for ${failures.length} session(s): ${detail}`,
        )
      }
    })()

View on GitHub (pinned to b150a551b8)

Solutions

1. Inspect the teardown error; the failure is logged and teardown continues, but fix the underlying resource release issue.

When it happens

Trigger: Thrown at packages/acp/acp/src/index.ts:490 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/3a95eecf26646032. Report an issue: GitHub.