# Problem of dependencies not found in TF 101 - Unit 2 and Unit 3

**URL:** <https://get-help.theconstruct.ai/t/problem-of-dependencies-not-found-in-tf-101-unit-2-and-unit-3/1230>\
**Category:** TF ROS 101\
**Created:** [October 28, 2019, 8:41am UTC](https://get-help.theconstruct.ai/t/problem-of-dependencies-not-found-in-tf-101-unit-2-and-unit-3/1230 "2019-10-28T08:41:29Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ttqwer1](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/ttqwer1/32/10_2.png) [@ttqwer1](https://get-help.theconstruct.ai/u/ttqwer1)\
**Post date:** [October 28, 2019, 8:41am UTC](https://get-help.theconstruct.ai/t/problem-of-dependencies-not-found-in-tf-101-unit-2-and-unit-3/1230/1 "2019-10-28T08:41:29Z")

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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.

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**Author:** ![duckfrost2](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/duckfrost2/32/9365_2.png) [@duckfrost2](https://get-help.theconstruct.ai/u/duckfrost2)\
**Post date:** [October 28, 2019, 3:11pm UTC](https://get-help.theconstruct.ai/t/problem-of-dependencies-not-found-in-tf-101-unit-2-and-unit-3/1230/2 "2019-10-28T15:11:37Z")

</div>

Thats an oddly strange issue. I just tried it here and no issue. Maybe there is something wrong in your catkin\_ws? Did you remove or compile something and gave error?  
Could you do the following:

> echo $ROS\_PACKAGE\_PATH

You should get this path:

> /home/user/catkin\_ws/src:/home/simulations/public\_sim\_ws/src:/opt/ros/kinetic/share

This allows the ros system to find all the packages.

Also, remove everything you have in the /home/user/catkin\_ws/src, (EXCEPT for the Cmakelitsts.txt ) , andtry to do:

> cd /homeUser/catkin\_ws; rm -rf build devel; source /home/simulations/public\_sim\_ws/devel/setup.bash; catkin\_make

This would reset the catkin\_ws with its original state, just in case, something went wrong in the comilation.

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<div class="post-metadata">

**Author:** ![SafdarKureishy](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/safdarkureishy/32/10_2.png) [@SafdarKureishy](https://get-help.theconstruct.ai/u/SafdarKureishy)\
**Post date:** [November 3, 2019, 4:47am UTC](https://get-help.theconstruct.ai/t/problem-of-dependencies-not-found-in-tf-101-unit-2-and-unit-3/1230/3 "2019-11-03T04:47:50Z")

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Thanks @duckfrost. I had the same issue. It got resolved when I reset the workspace (by switching to another chapter and then returning). So, it might have been some environment setting that got set incorrectly when rebuilding the workspace using catkin\_make. Thanks for your reply…it is a helpful reference.