somehow I am struggling with finding out whether it is possible to define an imported library in CMake, specifying target properties (include_directories and library path) a
The difference between the INCLUDE_DIRECTORIES property and the INTERFACE_INCLUDE_DIRECTORIES property is transitivity.
INCLUDE_DIRECTORIES
INTERFACE_INCLUDE_DIRECTORIES
Set INTERFACE_INCLUDE_DIRECTORIES instead.
http://www.cmake.org/cmake/help/v3.0/manual/cmake-buildsystem.7.html#transitive-usage-requirements