Turtlebot RaySensor race condition

edit

Hi. When running turtlebot i keep getting a warning message

 Warning [RaySensor.cc:206] ranges not constructed yet (zero sized)

I understand from this website that it can be solved by moving a small part of the code upward. However, when I did a "locate" on the file RaySensor.cc, all the RaySensor.cc appears to be in the trash folder

chengxiang@ubuntu:~$ locate RaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.0.1/src/physics/bullet 
/BulletRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.0.1/src/sensors/GpuRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.0.1/src/sensors/RaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.2.0.1/src/physics/bullet   
/BulletRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.2.0.1/src/sensors 
/GpuRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.2.0.1/src/sensors/RaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.3.0.1/src/physics/bullet 
/BulletRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.3.0.1/src/sensors 
/GpuRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.3.0.1/src/sensors/RaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.4.0.1/build/src/sensors  
/CMakeFiles/gazebo_sensors.dir/GpuRaySensor.cc.o
/home/chengxiang/.local/share/Trash/files/gazebo-1.4.0.1/build/src/sensors 
/CMakeFiles/gazebo_sensors.dir/RaySensor.cc.o
/home/chengxiang/.local/share/Trash/files/gazebo-1.4.0.1/src/physics/bullet  
/BulletRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.4.0.1/src/sensors 
/GpuRaySensor.cc
/home/chengxiang/.local/share/Trash/files/gazebo-1.4.0.1/src/sensors/RaySensor.cc

May i know how can i find the file or is there another way of solving this issue? I am using ROS fuerte with Ubuntu 12.04. Thank you in advance.

update 1

An error occurs when launching turtlebot after i install from source using

rosws set simulator_gazebo --svn https://code.ros.org/svn/ros-pkg/stacks
/simulator_gazebo/trunk

Error message :

[spawn_turtlebot_model-3] process has died [pid 7428, exit code 1, cmd  
/home/chengxiang/sim_workspace/simulator_gazebo/gazebo/scripts/spawn_model  
-unpause -urdf -param robot_description -model turtlebot  
__name:=spawn_turtlebot_model __log:=/home/chengxiang/.ros/log/277d87f4-1c4d- 
11e2-92d5-0017c4794a79/spawn_turtlebot_model-3.log].
log file: /home/chengxiang/.ros/log/277d87f4-1c4d-11e2-92d5-0017c4794a79  
/spawn_turtlebot_model-3*.log