Problem with ROS tutorial

edit

You probably need to source devel/setup.bash(or whatever shell you use)

the devel directory appears after the first build of your workspace.

To edit .bashrc on ubuntu type in the terminal:

gedit ~/.bashrc

.bashrc is a file in your home directory (/home/your_user_name). It is a bash script which is executed each time you start a bash terminal. One of the things it does is set up environment variables like e.g. paths to your ROS packages if you add the line source devel/setup.bash to the bottom.

Possibly, it is related with your workspace and package path. Please make sure that you sourced the bash file, i.e; source /home/<username>/catkin_ws/devel/setup.bash

If so, your package setup may be the problem. Your package should be listed when you run rospack find beginner_tutorials .

If these are not related, please supply more details like directory tree of your workspace and contents of package.xml file.