I've had some problems compiling the crystal branch of ROS2 from source with log4cxx for Ubuntu 16.04. When compiling with RCL_LOGGING_IMPLEMENTATION set to rcl_logging_log4cxx, I get the following warning for many packages:

Package 'rcl_logging_log4cxx' exports the include directory
'/home/rsa/ws/ros2/underlay_desktop/install/rcl_logging_log4cxx/share/rcl_logging_log4cxx/cmake/../../../include'
which doesn't exist

The build finally fails on:

CMake Error in CMakeLists.txt:
Imported target "rviz_common::rviz_common" includes non-existent path
"/home/rsa/ws/ros2/underlay_desktop/install/rcl_logging_log4cxx/include"
in its INTERFACE_INCLUDE_DIRECTORIES.

I've fixed it by adding to CMakeLists of rcl_logging_log4cxx:

install(DIRECTORY include/${PROJECT_NAME}
  DESTINATION include/${PROJECT_NAME}
)

After this, everything compiles and works. Is this the "correct" solution? If yes, I can create a pull request.