ros2 runtime_error ai_generated true

RuntimeError: Cannot cancel goal that is already being cancelled

ID: ros2/nav2-cancel-goal-multiple-times

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85%Fix Rate

85%Confidence

1Evidence

2024-02-15First Seen

Version Compatibility

Version	Status	Introduced	Deprecated	Notes
ros2-humble	active	—	—	—
ros2-iron	active	—	—	—
ros2-rolling	active	—	—	—

Root Cause

Nav2 action server does not support concurrent cancel requests on the same goal; calling cancel multiple times triggers a race condition in the action server's internal state machine.

generic

中文

Nav2动作服务器不支持对同一目标并发取消请求；多次调用取消会触发动作服务器内部状态机的竞态条件。

Official Documentation

https://docs.nav2.org/behavior_trees/overview.html

Workarounds

90% success Check if the goal is already in a terminal state before calling cancel: if (goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_ACCEPTED || goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_EXECUTING) { goal_handle->cancel(); }
```
Check if the goal is already in a terminal state before calling cancel: if (goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_ACCEPTED || goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_EXECUTING) { goal_handle->cancel(); }
```
85% success Use a mutex to serialize cancel calls: std::lock_guard<std::mutex> lock(cancel_mutex_); if (!cancel_in_progress_) { cancel_in_progress_ = true; goal_handle->cancel(); cancel_in_progress_ = false; }
```
Use a mutex to serialize cancel calls: std::lock_guard<std::mutex> lock(cancel_mutex_); if (!cancel_in_progress_) { cancel_in_progress_ = true; goal_handle->cancel(); cancel_in_progress_ = false; }
```

中文步骤

在取消前检查目标是否处于终端状态：if (goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_ACCEPTED || goal_handle->get_status() == action_msgs::msg::GoalStatus::STATUS_EXECUTING) { goal_handle->cancel(); }

使用互斥锁序列化取消调用：std::lock_guard<std::mutex> lock(cancel_mutex_); if (!cancel_in_progress_) { cancel_in_progress_ = true; goal_handle->cancel(); cancel_in_progress_ = false; }

Dead Ends

Common approaches that don't work:

70% fail
Race still occurs if two cancel calls happen within the sleep window; not a deterministic fix.
60% fail
Error is suppressed but the action server state may remain inconsistent, leading to future crashes.