seg fault on emitWakeUpSignal call in the result_callback lamda function #115

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1. saravan-kumar commented on Jul 15, 2025

   

   saravan-kumar

   on Jul 15, 2025

   Last edited by saravan-kumar

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   Writing a clear description on the issue and how to reproduce it in this comment.

   Issue

   I have BT executor, and I start executing a tree with a just a sequence and ROS action client in this sequence. I cancel this goal, and the result request for cancel times out and when i start executing the tree again, the delayed result is now being processed and the result tries to wake up a already exited tree, resulting in a seq fault

   To Reproduce

   Steps to reproduce the issue using btcpp_ros2_samples pkg

   1. Add this sleep in line 68 to reproduce a delay in the result from the server

   + rclcpp::sleep_for(std::chrono::seconds(3));

   BehaviorTree.ROS2/btcpp_ros2_samples/src/sleep_server.cpp

   Lines 67 to 73 in 7a6ace6

   	if(goal_handle->is_canceling())
   	{
   	result->done = false;
   	goal_handle->canceled(result);
   	RCLCPP_INFO(this->get_logger(), "Goal canceled");
   	return;
   	}

   
   2. Use this behaviour tree :

   <root BTCPP_format="4">
     <BehaviorTree ID="SleepActionSample2">
       <Sequence>
         <SaySomething message="start"/>
         <SleepAction name="sleepA" action_name="sleep_service" msec="20000"/>
         <SaySomething message="sleep completed"/>
       </Sequence>
     </BehaviorTree>
   </root>
   

   3. Build the package
   4. Run the sample_bt_executor that launches both the bt_executor and sleep server with

   ros2 launch btcpp_ros2_samples sample_bt_executor.launch.xml
   

   5. Start executing the tree:

   ros2 action send_goal /behavior_server btcpp_ros2_interfaces/action/ExecuteTree "{target_tree: SleepActionSample2}"
   

   6. Cancel the goal using:

   ros2 service call /behavior_server/_action/cancel_goal action_msgs/srv/CancelGoal
   

   7. Now do Step 5 again and it shoud crash

   ENVIRONMENT:

   • ROS Version humble
   • BT.ROS2 branch - humble

   Error Details from GDB Bt

   Thread 35 "sample_bt_execu" received signal SIGSEGV, Segmentation fault.
   [Switching to Thread 0x7fffd37ee640 (LWP 1081281)]
   0x00007ffff7be7608 in BT::TreeNode::emitWakeUpSignal() () from /home/saravana/do
   cker22.04/ddiplus_ws/install/behaviortree_cpp/lib/libbehaviortree_cpp.so
   (gdb) bt
   #0  0x00007ffff7be7608 in BT::TreeNode::emitWakeUpSignal() ()
      from /ws/install/behaviortree_cpp/lib/libbe
   haviortree_cpp.so
   #1  0x00007ffff03bd6f1 in BT::RosActionNode<btcpp_ros2_interfaces::action::Sleep
   >::tick()::{lambda(rclcpp_action::ClientGoalHandle<btcpp_ros2_interfaces::action
   ::Sleep>::WrappedResult const&)#3}::operator()(rclcpp_action::ClientGoalHandle<b
   tcpp_ros2_interfaces::action::Sleep>::WrappedResult const&) const ()
      from /ws/install/btcpp_ros2_samples/share/b
   tcpp_ros2_samples/bt_plugins/libsleep_plugin.so
   #2  0x00007ffff03c9077 in void std::__invoke_impl<void, BT::RosActionNode<btcpp_
   ros2_interfaces::action::Sleep>::tick()::{lambda(rclcpp_action::ClientGoalHandle
   <btcpp_ros2_interfaces::action::Sleep>::WrappedResult const&)#3}&, rclcpp_action
   ::ClientGoalHandle<btcpp_ros2_interfaces::action::Sleep>::WrappedResult const&>(
   std::__invoke_other, BT::RosActionNode<btcpp_ros2_interfaces::action::Sleep>::ti
   ck()::{lambda(rclcpp_action::ClientGoalHandle<btcpp_ros2_interfaces::action::Sle
   ep>::WrappedResult const&)#3}&, rclcpp_action::ClientGoalHandle<btcpp_ros2_inter
   faces::action::Sleep>::WrappedResult const&) ()