I'm working on a ROS2 (Humble) package called signal_pkg inside my workspace:

~/Dev/Projekte/ros2/rosmaster_ws/src/signal_pkg/

It contains two C++ nodes:

normal_pub.cpp (publisher)

blinker_sub.cpp (subscriber)

My structure looks like this:

rosmaster_ws/

|-src/

└── blinker_pkg/

   ├── CMakeLists.txt

   ├── package.xml

   └── src/

       ├── normal_pub.cpp

       └── blinker_sub.cpp

Github link to the code:

Both CMakeLists.txt and package.xml use the name signal_pkg.

What works:

colcon build finishes successfully

The executables normal_pub and blinker_sub appear in:

install/blinker_pkg/lib/blinker_pkg/

package.xml is installed correctly in:

install/blinker_pkg/share/blinker_pkg/package.xml

Additional (possibly related) build warning:

During every build I see this warning but 2just in this WS:

CMake Warning:
  Manually-specified variables were not used by the project:
    CATKIN_INSTALL_INTO_PREFIX_ROOT

I'm not using Catkin, but it still appears. I'm not sure where this is coming from. I never used ros1.

What doesn’t work:

Even after source install/setup.bash, running:

ros2 pkg list | grep blinker_pkg

returns nothing, and:

ros2 run blinker_pkg blinker_sub

returns:

Package 'blinker_pkg' not found

What am i missing?