HKUDS/nanobot · error · RuntimeError

exec session manager is closed

Error message

exec session manager is closed

What it means

Error "exec session manager is closed" thrown in HKUDS/nanobot.

Source

Thrown at nanobot/agent/tools/exec_session.py:293

        self._lock = asyncio.Lock()
        self._closed = False

    async def start(
        self,
        *,
        command: str,
        cwd: str,
        env: dict[str, str],
        timeout: int | None,
        shell_program: str | None,
        login: bool,
        yield_time_ms: int,
        max_output_chars: int,
        owner_session_key: str | None = None,
    ) -> tuple[str, _SessionPoll]:
        async with self._lock:
            if self._closed:
                raise RuntimeError("exec session manager is closed")
            await self._cleanup_locked()
            if len(self._sessions) >= self.max_sessions:
                raise RuntimeError(f"maximum exec sessions reached ({self.max_sessions})")
            process = await self._spawn(command, cwd, env, shell_program, login)
            session_id = uuid.uuid4().hex[:12]
            session = _ExecSession(
                session_id=session_id,
                process=process,
                command=command,
                cwd=cwd,
                timeout=timeout,
                owner_session_key=owner_session_key,
                process_tree=True,
            )
            self._sessions[session_id] = session

        poll = await session.poll(yield_time_ms, max_output_chars)
        if poll.done:

View on GitHub (pinned to 42f37dc4c0)

When it happens

Trigger: Thrown at nanobot/agent/tools/exec_session.py:293 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of HKUDS/nanobot@42f37dc4c0 (2026-08-26). Data as JSON: /api/errors/04b35dd8522a96a8. Report an issue: GitHub.