gazebo crashes on start, shared_ptr error.

edit

Hi! I was writing a plugin for a NXT robot I made and after studying erratic's diffdrive_plugin and turtlebot's gazebo_ros_create I think it's ready for a first test ride. But when I try to launch my robot (with a launch file of my own), and a .urdf.xacro of my own(inspired by erratic's and turtlebot's too) I get this error:

started core service [/rosout]
process[gazebo-2]: started with pid [11942]
process[spawn_robot-3]: started with pid [11943]
process[robot_state_publisher-4]: started with pid [11944]
Gazebo multi-robot simulator, version 0.10.0

Part of the Player/Stage Project [http://playerstage.sourceforge.net].
Copyright (C) 2003 Nate Koenig, Andrew Howard, and contributors.
Released under the GNU General Public License.

Param [quickStepPreconIters] is deprecated: [replace quickStepPreconIters with stepPreconIters]
Param [quickStep] is deprecated: [replace quickStep with stepType]
Param [quickStepIters] is deprecated: [replace quickStepIters with stepIters]
Param [quickStepW] is deprecated: [replace quickStepW with stepW]
ScopedName[gplane]
ScopedName[point_white]
Gazebo successfully initialized
[ INFO] [1333588639.189278494]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[INFO] [WallTime: 1333588639.485998] [0.001000] waiting for service spawn_urdf_model
gazebo: /usr/include/boost/smart_ptr/shared_ptr.hpp:418: T* boost::shared_ptr<T>::operator->() const [with T = urdf::Inertial]: Assertion `px != 0' failed.
[ERROR] [WallTime: 1333588639.555503] [0.001000] Service call failed: transport error completing service call: unable to receive data from sender, check sender's logs for details
[gazebo-2] process has died [pid 11942, exit code -6].
log files: /home/capelare/.ros/log/15a68e96-7ebd-11e1-9ab0-e0cb4e93305d/gazebo-2*.log
[spawn_robot-3] process has finished cleanly.
log file: /home/capelare/.ros/log/15a68e96-7ebd-11e1-9ab0-e0cb4e93305d/spawn_robot-3*.log

I understand that I'm using a shared pointer without having initialized it first... maybe it's something about the subscriber to the cmd_vel node? :-\

This is the content of the spawn_robot-3.log file, BTW, there's no gazebo-2*.log file:

[rospy.client][INFO] 2012-04-05 03:17:18,230: init_node, name[/spawn_robot], pid[11943]
[xmlrpc][INFO] 2012-04-05 03:17:18,230: XML-RPC server binding to 0.0.0.0
[xmlrpc][INFO] 2012-04-05 03:17:18,231: Started XML-RPC server [http://Ubunti7:46395/]
[rospy.init][INFO] 2012-04-05 03:17:18,231: ROS Slave URI: [http://Ubunti7:46395/]
[rospy.impl.masterslave][INFO] 2012-04-05 03:17:18,231: _ready: http://Ubunti7:46395/
[rospy.registration][INFO] 2012-04-05 03:17:18,232: Registering with master node http://localhost:11311
[xmlrpc][INFO] 2012-04-05 03:17:18,232: xml rpc node: starting XML-RPC server
[rospy.init][INFO] 2012-04-05 03:17:18,331: registered with master
[rospy.rosout][INFO] 2012-04-05 03:17:18,367: initializing /rosout core topic
[rospy.rosout][INFO] 2012-04-05 03:17:18,369: connected to core topic /rosout
[rospy.simtime][INFO] 2012-04-05 03:17:18,370: initializing /clock core topic
[rospy.simtime][INFO] 2012-04-05 03:17:18,371: connected to core topic /clock
[rosout][INFO] 2012-04-05 03:17:19,485: waiting for service spawn_urdf_model
[rosout][ERROR] 2012-04-05 03:17:19,555: Service call failed: transport error completing service call: unable to receive data from sender, check sender's logs for details
[rospy.core ...