Expected include directory with Humble

edit

Hi,

When porting some packages from Foxy/Galactic to Humble I have noticed one additional level in the expected include directory, for example the one that is generated from messages:

Foxy / Galactic: <ros2_ws>/install/<pkg>/include/<pkg>/msg/headers.hpp
Humble:          <ros2_ws>/install/<pkg>/include/<pkg>/<pkg>/msg/headers.hpp

The ament_target_dependencies CMake line includes the right directory, depending on the ROS 2 distro.

However, when installing header files manually (to export some library), this is not automagic. Is is necessary to consider the ROS 2 distro to install the include directory or is there a better way? For now I can only do like:

if(Foxy or Galactic)  install(DIRECTORY include/ DESTINATION include)
else                  install(DIRECTORY include/ DESTINATION include/${PROJECT_NAME})