undefined reference to ... when compiling ros node - c++

Question

I'm trying to write a ROS-Node which uses OpenCV nonfree components (SURF). I have trouble compiling the package using catkin_make:
//usr/local/lib/libopencv_nonfree.so: undefined reference to `cv::ocl::integral(cv::ocl::oclMat const&, cv::ocl::oclMat&)'
CMakeLists.txt
cmake_minimum_required(VERSION 2.8.3)
project(homography_test)
## Find catkin macros and libraries
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
roscpp
rospy
std_msgs
sensor_msgs
cv_bridge
image_transport
)
catkin_package(
)
###########
## Build ##
###########
## Specify additional locations of header files
## Your package locations should be listed before other locations
# include_directories(include)
include_directories(
${catkin_INCLUDE_DIRS}
/usr/local/include
/usr/include
/usr/include/gstreamer-1.0
/usr/include/glib-2.0
/usr/lib/x86_64-linux-gnu/glib-2.0/include
)
## Declare a cpp executable
#add_executable(display_image src/display_image_node.cpp)
add_executable(homography src/sample.cpp)
## Add cmake target dependencies of the executable/library
## as an example, message headers may need to be generated before nodes
#add_dependencies(homography_test homography_test_generate_messages_cpp)
## Specify libraries to link a library or executable target against
target_link_libraries(
homography
${catkin_LIBRARIES}
gstreamer-1.0
gobject-2.0
glib-2.0
opencv_nonfree
opencv_calib3d
opencv_contrib
opencv_core
opencv_features2d
opencv_flann
opencv_gpu
opencv_highgui
opencv_imgproc
opencv_legacy
opencv_ml
opencv_objdetect
opencv_ocl
opencv_photo
opencv_stitching
opencv_superres
opencv_ts
opencv_video
opencv_videostab
rt
pthread
m
dl
)
link_directories(/usr/local/lib)
But if I manually compile the same code, but not as ROS-node, everything works.

Answer 1

It seems that the opencv_ocl library is not being linked properly. Also, you can simplify your CMakeLists.txt file a lot by using find_package to get your OpenCV configuration. Try adding those lines to your CMakeLists.txt file:
find_package(OpenCV REQUIRED core ocl)
include_directories(SYSTEM ${OpenCV_INCLUDE_DIRS})
target_link_libraries(homography ${catkin_LIBRARIES} ${OpenCV_LIBRARIES} )
You need to specify which OpenCV libraries you want to include in the find_package. I listed only core and ocl since ocl seems to be what you need, but others might be needed as well.