Problem with dependencies in TF 101 - Unit 4

It seems something is going wrong. I got an error when I execute the first exercise of Chapter 3 (Exercise 3.1a),

user:~$ roslaunch pi_robot_pkg pi_robot_control_norsp.launch
[pi_robot_control_norsp.launch] is neither a launch file in package [pi_robot_pkg] nor is [pi_robot_pkg] a launch file name
The traceback for the exception was written to the log file

I can’t even roscd to the pi_robot_pkg Directory:
user:~$ roscd pi_robot_pkg
roscd: No such package/stack ‘pi_robot_pkg’

Please help, Thanks a lot.

@ttqwer1,

I’m sorry we somehow missed this question :cold_sweat:. Were you able to get past it?