Callback of actionlib_msgs::GoalStatusArray fails

edit

Hi,

I am writing a node that subscribes to an actionlib_msgs::GoalStatusArray message. The callback code is:

  move_base_status_sub = n.subscribe<actionlib_msgs::GoalStatusArray>("/move_base/status", 50, &rviz_text::move_base_statusCallback, this);

...

void rviz_text::move_base_statusCallback(const actionlib_msgs::GoalStatusArrayConstPtr& msg)
{
  actionlib_msgs::GoalStatusArray status_array = *msg;   
  uint32_t sequence = status_array.header.seq;
  // sequence is read successfully 

  actionlib_msgs::GoalStatus status_list_entry = status_array.status_list[0]; 
  // status_list_entry is read unsuccessfully. The above line causes a seg fault at runtime. 
}

I am able to read the header of the GoalStatusArray, but unable to read the status_list array. I get a segmentation fault when doing so.

I seem to be doing an error when trying to access the first element of status_array.status_list. Do you see any syntax error in my code?

The GoalStatusArray and GoalStatus messages definitions can be found on:

GoalStatusArray message

GoalStatus message

My callback function is subscribing to the /move_base/status topic. The messages on this topic look like the following:

---
header: 
  seq: 52
  stamp: 
    secs: 1400564326
    nsecs: 841550350
  frame_id: ''
status_list: 
  - 
    goal_id: 
      stamp: 
        secs: 1400564318
        nsecs: 321941901
      id: /move_base-1-1400564318.321941901
    status: 1
    text: This goal has been accepted by the simple action server
---

My setup:

• ROS fuerte
• Ubuntu 12.04

Do you have a clue why my code is failing?