Error in Launch File detection

[Dhananjay_Panth]

Hello there,

I have been doing the “ROS2 Basics in 5 Days (Python)” course, and in the topic 2.7 creating a launch file, i am not able to launch the launch file for “Exercise 3”

I have followed all the steps so far, and when i come to the part where i have to launch the file using the command “ros2 launch”, it is showing that the file does not exist.

i have attached a screenshot of the whole console displaying the editor, file tree and terminal

Please help, if you need further clarification, please message

thanks in advance,
Dhananjay S Panth

Screenshot:

[jpvaldivia7]

Hi @Dhananjay_Panth, the error indicates that the two_rover_heartbeat.py file is not found in the share directory of the mars_rover_systems package. This typically happens due to a missing or incorrect configuration in the package’s setup.py. Can you share the setup.py? The problem must be there.

[Dhananjay_Panth]

Hi @jpvaldivia7 this is the code present inside setup.py :

from setuptools import find_packages, setup
import os
from glob import glob

package_name = ‘mars_rover_systems’

setup(
name=package_name,
version=‘0.0.0’,
packages=find_packages(exclude=[‘test’]),
data_files=[
(‘share/ament_index/resource_index/packages’,
[‘resource/’ + package_name]),
(‘share/’ + package_name, [‘package.xml’]),
(os.path.join(‘share’, package_name), glob(‘launch/*.launch.py’))
],
install_requires=[‘setuptools’],
zip_safe=True,
maintainer=‘user’,
maintainer_email=‘user@todo.todo’,
description=‘TODO: Package description’,
license=‘TODO: License declaration’,
tests_require=[‘pytest’],
entry_points={
‘console_scripts’: [
‘heartbeat_executable = mars_rover_systems.heartbeat:main’,
‘heartbeat_executable_2 = mars_rover_systems.heartbeat:main_2’
],
},
)

Would you like anything else?

P:S: The “setuptools” library always throws up an error, as seen in the above pic, it always shows "Import “setuptools” could not be resolved from sourcePylance(reportMissingModuleSource)
" When i did this course back in june, i had the same problem then, and now also. Same problem, In the same exercise. i dont know whether it is my fault, or something else…

[jpvaldivia7]

I can see the issue here, the problem is with the line:

(os.path.join('share', package_name), glob('launch/*.launch.py'))

You named your file two_rover_heartbeat.py and in the setup.py you are saying that it is a .launch.py so all you have to do is rename your script to two_rover_heartbeat.launch.py which is the extension for launch files in ROS2.

[Dhananjay_Panth]

Ah i see…

So i went ahead and renamed the “two_rover_heartbeat.py” into “two_rover_heartbeat.launch.py”, but now i am getting this:

What am i doing wrong

I even did “source install/setup.bash” and “colcon build”

[jpvaldivia7]

It seems the changes were not applied successfully. Here’s how you can verify and fix this:
Navigate to the install/share/mars_rover_systems/launch folder to ensure that the file with the updated name is present. You can do this with:

ls ~/ros2_ws/install/share/mars_rover_systems/launch/

Here you should see your two_rover_heartbeat.launch.py, if the file is not listed, it means the changes in your setup.py were not applied during the build process and you have to compile and source again.

[Dhananjay_Panth]

Sir it appears that there is no launch file, i.e, “two_rover_heartbeat.launch.py”, nor my launch folder inside the " share" folder…

This is my Folder tree, let me know if you need the titles of any other folders too…

How has this happened, and how do i fix this, i did compiling and sourcing again, but nothing happened…

[Dhananjay_Panth]

This is how my console looks now: (could’nt upload together)

[jpvaldivia7]

I found the error, in your folder tree you have the launch file inside the /mars_rover_systems/mars_rover_systems/launch and it should be /mars_rover_systems/launch, the launch folder must be at the same level as resource, test and mars_rover_systems folders as the notebook says. Make this correction and now I am sure that it will work.

[jpvaldivia7]

Here is how your folder tree should look like (just the mars_rover_systems package).

[Dhananjay_Panth]

Got it working @jpvaldivia7 Thanks a lot for your help