Adding laser sensors to Gazebo

Greetings, I have tried to add laser node to gazebo using the following code: but I got the following error: Invalid tag: Cannot load command parameter [robot_description]: command [/opt/ros/indigo/share/xacro/xacro.py /home/nouf/catkin_ws/src/chapter5_tutorials/urdf/robot1_base_03.xacro] returned with code [1]. Param xml is The traceback for the exception was written to the log file I found out that the erratic_description package doesn't work with indigo version (which I'm currently using). Is there another package or another way to add a laser node to Gazebo ? Thanks in advance.