Catkin adds hardcoded paths to auto-generated .cmake files

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Hi Dirk,

Thanks for the reply. So would you describe orocos_kdl as system package? Is it the fault of robot_state_publisher not using including the orocos_kdl package correctly hence the hardcoded paths?

OrocosKDLTargets.cmake and orocos_kdl-config.cmake files don't seem to use absolute paths yet the robot_state_publisher Config.cmake file still includes absolute paths to both include folder and library of orocos_kdl. This also happens with packages like Geometry2 when building tf2_kdl tests and kdl_conversions.

orocos_kdlis not a system package since it is listed as a ROS package in the distribution: https://github.com/ros/rosdistro/blob...

Its CMake config file does provide absolute path: set(orocos_kdl_INCLUDE_DIRS "${CMAKE_CURRENT_LIST_DIR}/../../../include;;/usr/include/eigen3").

When downstream packages like robot_state_publisher just call find_package(orocos_kdl) and catkin_package(DEPENDS orocos_kdl) it will result of that absolute path from orocos_kdl_INCLUDE_DIRS to be embedded in the CMake config file of that package.

So yes, the fault is at the downstream packages like robot_state_publisher. They should not export the dependency using DEPENDS but defer resolving the orocos_kdl dependency into a custom CMake extra file.

Ok great. Thank you for your response. Sorry for all the questions! I haven't found much information on this hard-coded path issue so hopefully this will clear it up for others too.

So does this happen because downstream packages are including plain .cmake packages? Why doesn't this happen when you declare a dependency to a catkin package? e.g catkin_package(DEPENDS <catkin_package>) without the need for a custom -extra.cmake file?

http://docs.ros.org/melodic/api/catki... Can I just follow this to adjust the packages that are depending on orocos_kdl incorrectly? Do I need to make a custom .cmake file or can I just include the orocos .cmake files for export? Do you know of any examples I could look at to make these custom .cmake files?

Thanks again!

catkin packages are treated differently by the logic exporting the information for DEPENDS: https://github.com/ros/catkin/blob/f9...

That is why it works automatically for catkin packages but not for others - simply because we can't assume that they adhere to a certain conventions.

You will need a custom <pkgname>-extras.cmake.*. It needs to call find_package(orocos_kdl REQUIRED) as well as combine all needed variables e.g. list(APPEND @PROJECT_NAME@_INCLUDE_DIRS ${orocos_kdl_INCLUDE_DIRS}), the same for *_LIBRARIES etc.

Perfect. Thank you very much for your help. I will give it a go.

Hi Dirk,

This worked just great thank you. However, I only needed the find_package(orocos_kdl REQUIRED) section and had to remove the list(APPEND @PROJECT_NAME@_... sections.

My reasoning below: In catkin_package.cmake

list(INSERT PROJECT_INCLUDE_DIRS 0 ${${PROJECT_NAME}_INCLUDE_DIRS})

https://github.com/ros/catkin/blob/f9...

This adds all ${PROJECT_NAME}_INCLUDE_DIRS to the variable PROJECT_INCLUDE_DIRS. Later on in the installation space this happens :

foreach(idir ${PROJECT_INCLUDE_DIRS})

if(IS_ABSOLUTE ${idir})

list_append_unique(PROJECT_CMAKE_CONFIG_INCLUDE_DIRS "${idir}")

So if I include the list(APPEND ... in the -extras.cmake file any consuming package of this package then adds the hardcoded paths to it's .cmake file in the install space.

Did I do something wrong or can you confirm this is ok?

Hm, you are right. That is indeed undesired. I don't understand how you are using the include directories / libraries of the found package if you don't pass the variables anywhere?

I don't need to pass the variables at build time due to find_package(orocos_kdl REQUIRED) in the -extras.cmake file setting orocos_kdl_LIBRARIES and orocos_kdl_INCLUDE_DIRS. Then in the future install any package that consumes that package will just have the -extras.cmake file automatically included and those libraries/headers will be found?