How can I generate pkg-config files for my package?

edit

I have a Catkin package that generates several binaries and libraries, but unlike some other packages, pkg-config can't find them.

ROS seems to have set the path to both my Kinetic installation, as well as my workspace.

echo $PKG_CONFIG_PATH 
somelocation/workspace/devel/lib/pkgconfig:somelocation/ros_catkin_ws/install_isolated/lib/pkgconfig

When I ask pkg-config --list-all about it, it does know about all of the ROS libraries, and also about things I installed in my own workspace, like joy and uuid. But it does not find the libraries I wrote myself.

I went over to the CMakeLists.txt of joy to see if I could find anything obvious that has to be done to generate the correct files, but can't see anything. There is no .pc file in the repo either. I also tried to google around, but all results are about using external packages inside ROS, not about using ROS package outside it.

Currently I'm just doing this, but that apparently does not get you any pkg-config files. Full source: https://github.com/RoboTeamTwente/rob...

  add_library(Skill
        $<TARGET_OBJECTS:treegen>
        $<TARGET_OBJECTS:tactics>
        $<TARGET_OBJECTS:utils>
        $<TARGET_OBJECTS:skills>
        $<TARGET_OBJECTS:conditions>
        )
  add_dependencies(Skill 
        ${${PROJECT_NAME}_EXPORTED_TARGETS}
        ${catkin_EXPORTED_TARGETS}
        )

When I run this, there is no output

$ pkg-config --list-all | grep -i skill

So what is the correct way to tell pkg-config about my library, just like joy and uuid?