dofbot@ubuntu:~/catkin_ws$ roslaunch learning_launch simple.launch
RLException: [simple.launch] is neither a launch file in package [learning_launch] nor is [learning_launch] a launch file name
The traceback for the exception was written to the log file
dofbot@ubuntu:~/catkin_ws$
小白一个,在别人给的系统里运行最简单的roslaunch,但是编译好像和视频都不一样。怎么都运行不了,我试过设置set.bash了很绝望