RLException: XXX is neither a launch file in package XXX nor is XXX a launch file name问题解决

在运行roslaunch时出现了类似下面的错误：

RLException: XXX is neither a launch file in package XXX nor is XXX a launch file name

这是因为setup.bash文件没有进一步说明包的来源，解决方法是

source catkin_ws/devel/setup.bash