新人求助,roslaunch报错

Traceback (most recent call last):
File “/opt/ros/melodic/lib/gazebo_ros/spawn_model”, line 29, in
from gazebo_ros import gazebo_interface
File “/opt/ros/melodic/lib/python2.7/dist-packages/gazebo_ros/gazebo_interface.py”, line 9, in
from gazebo_msgs.msg import *
ImportError: No module named msg
[spawn_model-5] process has died [pid 4348, exit code 1, cmd /opt/ros/melodic/lib/gazebo_ros/spawn_model -file /home/wdx/catkin_ws/src/car4/urdf/car4.urdf -urdf -model car4 __name:=spawn_model __log:=/home/wdx/.ros/log/8b1aa174-464d-11eb-928a-2b38df8a44f4/spawn_model-5.log].
log file: /home/wdx/.ros/log/8b1aa174-464d-11eb-928a-2b38df8a44f4/spawn_model-5*.log

我的系统是Ubuntu18.04,ros_melodic,gazebo9.0

你好,建议升级gazebo到9.10以上。这个问题可能是gazebo的依赖没有完全安装,可以先单独执行gazebo启动试试看。