Error : Package 'topic_publisher_pkg' not found

[vincent.begoc]

Hi,

I am stuck at the end of Exercise 3.1 Topic Publishers.

I created a new package,
then created the cpp file in the corresponding folder,
then created a launch file in a launch folder (in the package folder) (I am not so sure where this file is supposed to be…).

I compiled the package and it seemed to work :

user:~/ros2_ws$ colcon build --packages-select topic_publisher_pkg
Starting >>> topic_publisher_pkg
Finished <<< topic_publisher_pkg [17.3s]

But, when I try to launch the programm I get this error :

user:~/ros2_ws$ ros2 launch topic_publisher_pkg simple_topic_publisher.launch.py
Package ‘topic_publisher_pkg’ not found: “package ‘topic_publisher_pkg’ not found, searching: [‘/home/simulations/ros2_sims_ws/install/move_robot_as’, ‘/home/simulations/ros2_sims_ws/install/t3_action_msg’, ‘/home/simulations/ros2_sims_ws/install/services_pkg’, ‘/home/simulations/ros2_sims_ws/install/parameter_tests’, ‘/home/simulations/ros2_sims_ws/install/neo_simulation2’, ‘/home/simulations/ros2_sims_ws/install/aws_robomaker_small_warehouse_world’, ‘/opt/ros/humble’]”

Can you please help me with this issue ?

Thanks for the feedback.

Vincent

[duckfrost2]

Hi,

Can you paste the Cmakelist.txt contents?
Did you source after compiling?
Does the double tab autocomplete the package?

[vincent.begoc]

Hello duckfrost2,
Thanks for your help.

Below is the Cmakelist.txt
I dit source after compiling.
I don’t get your last question…

cmake_minimum_required(VERSION 3.8)
project(topic_publisher_pkg)

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES “Clang”)
add_compile_options(-Wall -Wextra -Wpedantic)
endif()

find dependencies

find_package(ament_cmake REQUIRED)
find_package(rclcpp REQUIRED)
find_package(std_msgs REQUIRED)

if(BUILD_TESTING)
find_package(ament_lint_auto REQUIRED)

the following line skips the linter which checks for copyrights

comment the line when a copyright and license is added to all source files

set(ament_cmake_copyright_FOUND TRUE)

the following line skips cpplint (only works in a git repo)

comment the line when this package is in a git repo and when

a copyright and license is added to all source files

set(ament_cmake_cpplint_FOUND TRUE)
ament_lint_auto_find_test_dependencies()
endif()
add_executable(simple_publisher_node src/simple_topic_publisher.cpp)
ament_target_dependencies(simple_publisher_node rclcpp std_msgs)

install(TARGETS
simple_publisher_node
DESTINATION lib/${PROJECT_NAME}
)

Install launch files.

install(DIRECTORY
launch
DESTINATION share/${PROJECT_NAME}/
)
ament_package()

[CCAnabeza]

Hi @vincent.begoc,

Regarding the double tab referred by @duckfrost2, this pertains to an action in your Command Line Interface (CLI) from which once you are to input a package that you are unsure of, ROS2 has this feature or functionality that allows for the autocompletion of file names within a specific directory. So in this case, if you are able to see your package “pop-up” into the CLI after performing a double tab, I believe this impilies that your package is available and has been detected by your system.

Regards,
Christian

[CCAnabeza]

Greetings once again, @vincent.begoc!

I noticed that your package is inside the workspace folder itself, ros2_ws. I believe this should be created within the /src folder instead.

Please do try navigating to your /src folder and then run the syntax “ros2 pkg create topic_publisher_pkg --build-type dependency_1 dependency_2 dependency_n”

Hope this helps!

Kind regards,
Christian

[vincent.begoc]

Thanks CCAnabeza,
I did the correction you suggested (after suppressing the /ros2_ws/build/ folder and the topic_publisher_pkg folder) and it works now.
Many thanks for your help !
Vincent

[CCAnabeza]

All the best, @vincent.begoc!

Glad I could help.