rohitg00/ai-engineering-from-scratch · error · RuntimeError

run() requires IDLE, got {self.state.value}

Error message

run() requires IDLE, got {self.state.value}

What it means

Error "run() requires IDLE, got {self.state.value}" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/19-capstone-projects/20-agent-harness-loop-contract/code/main.py:216

    def _check_budget(self) -> PullRequest | None:
        which = self.budget.exceeded()
        if which is None:
            return None
        self._emit("budget.warn", {"limit": which})
        self.hooks.fire("on_budget_exceeded", {"limit": which, "budget": self.budget})
        self._reason = f"budget_exceeded:{which}"
        self._prev_state = self.state
        return self._pause(self._reason)

    def _pause(self, reason: str) -> PullRequest:
        self._emit("session.pause", {"reason": reason})
        self.hooks.fire("on_pause", {"reason": reason})
        self._transition(State.IDLE)
        return PullRequest(reason=reason, state=self.state, payload={"reason": reason})

    def run(self, goal: str) -> PullRequest | SessionResult:
        if self.state != State.IDLE:
            raise RuntimeError(f"run() requires IDLE, got {self.state.value}")
        self._goal = goal
        self.budget.started_at = time.time()
        self._emit("session.start", {"goal": goal})
        return self._step()

    def resume(self, payload: dict | None = None) -> PullRequest | SessionResult:
        if self.state == State.IDLE and self._reason.startswith("budget_exceeded"):
            self.budget.turns = 0
            self.budget.tool_calls = 0
            self.budget.started_at = time.time()
            self._reason = ""
            prev = self._prev_state
            self._prev_state = None
            if not self._plan:
                return self._begin_plan()
            if prev == State.EXECUTING:
                self.state = State.EXECUTING
            else:

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/19-capstone-projects/20-agent-harness-loop-contract/code/main.py:216 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/5295b29c7174ca7b. Report an issue: GitHub.