bytedance/deer-flow · error · TimeoutError

Timed out acquiring memory scope lock {lock_path}

Error message

Timed out acquiring memory scope lock {lock_path}

What it means

Error "Timed out acquiring memory scope lock {lock_path}" thrown in bytedance/deer-flow.

Source

Thrown at backend/packages/harness/deerflow/agents/memory/backends/deermem/deermem/core/storage.py:370

        while not acquired:
            try:
                if os.name == "nt":
                    import msvcrt

                    handle.seek(0, os.SEEK_END)
                    if handle.tell() == 0:
                        handle.write(b"0")
                        handle.flush()
                    handle.seek(0)
                    msvcrt.locking(handle.fileno(), msvcrt.LK_NBLCK, 1)
                else:
                    import fcntl

                    fcntl.flock(handle.fileno(), fcntl.LOCK_EX | fcntl.LOCK_NB)
                acquired = True
            except OSError:
                if time.monotonic() >= deadline:
                    raise TimeoutError(f"Timed out acquiring memory scope lock {lock_path}")
                time.sleep(0.05)
        yield
    finally:
        if acquired:
            try:
                if os.name == "nt":
                    import msvcrt

                    handle.seek(0)
                    msvcrt.locking(handle.fileno(), msvcrt.LK_UNLCK, 1)
                else:
                    import fcntl

                    fcntl.flock(handle.fileno(), fcntl.LOCK_UN)
            except OSError:
                logger.warning("Failed to release memory scope lock %s", lock_path)
        handle.close()

View on GitHub (pinned to 1dd6ba1acb)

Solutions

1. Check for a stale lock file at the named lock_path and remove it if no process holds it.
2. Reduce concurrent memory writers; retry after the current writer releases the lock.

When it happens

Trigger: Thrown at backend/packages/harness/deerflow/agents/memory/backends/deermem/deermem/core/storage.py:370 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

AI-assisted analysis of bytedance/deer-flow@1dd6ba1acb (2026-08-14). Data as JSON: /api/errors/e328db18cfdee136. Report an issue: GitHub.