我在试着逃跑：-
roslaunch海龟机器人_凉亭海龟机器人_世界。启动
但我收到以下错误

Traceback (most recent call last):
  File "/opt/ros/kinetic/share/xacro/xacro.py", line 55, in <module>
    import xacro
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/xacro/__init__.py", line 42, in <module>
    from roslaunch import substitution_args
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/__init__.py", line 56, in <module>
    from .launch import ROSLaunchRunner
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/launch.py", line 55, in <module>
    from roslaunch.nodeprocess import create_master_process, create_node_process
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/nodeprocess.py", line 49, in <module>
    from roslaunch.node_args import create_local_process_args
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/node_args.py", line 53, in <module>
    import roslib.packages
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslib/__init__.py", line 54, in <module>
    import roslib.stacks
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslib/stacks.py", line 46, in <module>
    import roslib.packages
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslib/packages.py", line 49, in <module>
    from catkin.find_in_workspaces import find_in_workspaces as catkin_find
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/catkin/find_in_workspaces.py", line 36, in <module>

from catkin_pkg.packages import find_packages
ImportError: No module named catkin_pkg.packages
while processing /opt/ros/kinetic/share/turtlebot_gazebo/launch/includes/kobuki.launch.xml:
Invalid <param> tag: Cannot load command parameter [robot_description]: command [/opt/ros/kinetic/share/xacro/xacro.py '/opt/ros/kinetic/share/turtlebot_description/robots/kobuki_hexagons_asus_xtion_pro.urdf.xacro'] returned with code [1].