Hi Georg,

your problem is related to an issue I posted in the catkin bugtracker a
while ago:
https://github.com/ros/catkin/issues/535

Unfortunately catkin_package(DEPENDS orocos_kdl) only exports the
orocos_kdl_LIBRARIES and orocos_kdl_INCLUDE_DIRS flags to dependent
packages, so the LIBRARY_DIRS variable gets lost. That's why your somenode
package cannot find liborocos-kdl.so. What needs to be done according to
wjwwood's answer on Github is to expand the orocos_kdl_LIBRARIES variable
to its full path by calling find_library() before the call to
catkin_package(...). Either this has to be added in the orocos_kdl cmake
config file or you can add it after the find_package(orocos_kdl REQUIRED)
line in somelib/CMakeLists.txt:

find_package(orocos_kdl REQUIRED)

# Find the absolute path to the orocos-kdl library
find_library(orocos_kdl_LIBRARY NAMES ${orocos_kdl_LIBRARIES} PATHS
${orocos_kdl_LIBRARY_DIRS} NO_DEFAULT_PATH)
set(orocos_kdl_LIBRARIES ${orocos_kdl_LIBRARY})

catkin_package(... DEPENDS orocos_kdl)

With that patch I could compile your example successfully in hydro. Another
possible workaround is to let somenode also depend on orocos_kdl and to add
the link_directories(...) line as you did in somelib.

Regards,
Johannes

On Wed, Nov 20, 2013 at 5:45 PM, Georg Bartels <
georg [dot] bartels [..] ...> wrote:

> Dear Orocos-Users,
>
> I'm trying to use KDL in ROS Hydro with catkin. I encountered the
> following a linker error which I could not resolve, so far.
>
> I understand that this could be considered a ROS/catkin-specific
> question. However, I suspect the reason to be related to the way catkin
> is compiled and release in ROS Hydro, i.e. mixed cmake/catkin. Hence,
> the question on this mailing list. Please point me to any more related
> point of questioning, if existent. ;)
>
> OK, here comes my situation:
>
> (1) I have a cpp-library 'Mylib' in the catkin ROS package 'somelib'.
> This library links against KDL, and compiles and links fine.
>
> (2) The ROS package 'somelib' declares orocos_kdl as a system dependency
> which depending packages also need.
>
> (3) I have a cpp-executable 'MyNode' in the catkin package 'somenode'
> which links against 'somelib' and itself does not use any KDL
> functionality. Still, linking of somenode fails on kdl:
>
> Linking CXX executable
> /home/georg/ros/hydro/catkin_ws2/devel/lib/somenode/somenode_node
> /usr/bin/ld: cannot find -lorocos-kdl
>
> (4) Strangely, orocos_kdl is actually part of the catkin_LIBRARIES
> variable:
>
>
> catkin_LIBRARIES=/opt/ros/hydro/lib/libroscpp.so;/usr/lib/x86_64-linux-gnu/libpthread.so;/usr/lib/libboost_signals-mt.so;/usr/lib/libboost_filesystem-mt.so;/usr/lib/libboost_system-mt.so;/opt/ros/hydro/lib/libcpp_common.so;/opt/ros/hydro/lib/libroscpp_serialization.so;/opt/ros/hydro/lib/librostime.so;/usr/lib/libboost_date_time-mt.so;/usr/lib/libboost_thread-mt.so;/opt/ros/hydro/lib/librosconsole.so;/usr/lib/libboost_regex-mt.so;/usr/lib/liblog4cxx.so;/opt/ros/hydro/lib/libxmlrpcpp.so;somelib;/opt/ros/hydro/lib/liborocos-kdl.so
>
> I have uploaded my code on the following repo:
>
> https://github.com/airballking/orocos_hydro
>
> What do I need to export/declare such that packages depending on the ROS
> package 'somelib' automatically get orocos_kdl, as well? Did anyone
> already encounter/solve this problem? Thanks already!
>
> Best,
> Georg.
> --
> Orocos-Users mailing list
> Orocos-Users [..] ...
> http://lists.mech.kuleuven.be/mailman/listinfo/orocos-users
>

Hi Bartel,

Op woensdag 20 november 2013 schreef Georg Bartels (
georg [dot] bartels [..] ...):

> Dear Orocos-Users,
>
> I'm trying to use KDL in ROS Hydro with catkin. I encountered the
> following a linker error which I could not resolve, so far.
>
> I understand that this could be considered a ROS/catkin-specific
> question. However, I suspect the reason to be related to the way catkin
> is compiled and release in ROS Hydro, i.e. mixed cmake/catkin. Hence,
> the question on this mailing list. Please point me to any more related
> point of questioning, if existent. ;)
>
> OK, here comes my situation:
>
> (1) I have a cpp-library 'Mylib' in the catkin ROS package 'somelib'.
> This library links against KDL, and compiles and links fine.
>
> (2) The ROS package 'somelib' declares orocos_kdl as a system dependency
> which depending packages also need.
>
> (3) I have a cpp-executable 'MyNode' in the catkin package 'somenode'
> which links against 'somelib' and itself does not use any KDL
> functionality. Still, linking of somenode fails on kdl:
>
> Linking CXX executable
> /home/georg/ros/hydro/catkin_ws2/devel/lib/somenode/somenode_node
> /usr/bin/ld: cannot find -lorocos-kdl
>
> (4) Strangely, orocos_kdl is actually part of the catkin_LIBRARIES
> variable:
>
>
> catkin_LIBRARIES=/opt/ros/hydro/lib/libroscpp.so;/usr/lib/x86_64-linux-gnu/libpthread.so;/usr/lib/libboost_signals-mt.so;/usr/lib/libboost_filesystem-mt.so;/usr/lib/libboost_system-mt.so;/opt/ros/hydro/lib/libcpp_common.so;/opt/ros/hydro/lib/libroscpp_serialization.so;/opt/ros/hydro/lib/librostime.so;/usr/lib/libboost_date_time-mt.so;/usr/lib/libboost_thread-mt.so;/opt/ros/hydro/lib/librosconsole.so;/usr/lib/libboost_regex-mt.so;/usr/lib/liblog4cxx.so;/opt/ros/hydro/lib/libxmlrpcpp.so;somelib;/opt/ros/hydro/lib/liborocos-kdl.so
>
> I have uploaded my code on the following repo:
>
> https://github.com/airballking/orocos_hydro
>
> What do I need to export/declare such that packages depending on the ROS
> package 'somelib' automatically get orocos_kdl, as well? Did anyone
> already encounter/solve this problem? Thanks already!
>
>
Could you provide the output of "make VERBOSE=1", so we can see the exact
linker command?

Ruben

> Best,
> Georg.
> --
> Orocos-Users mailing list
> Orocos-Users [..] ... <javascript:;>
> http://lists.mech.kuleuven.be/mailman/listinfo/orocos-users
>