Linking error while compiling opencv with cuda on high sierra - macos

Question

I am getting a linking error while compiling opencv with cuda on Mac OS X high Sierra (10.13.6).
Error message:
[ 21%] Linking CXX shared library ../../lib/libopencv_cudev.dylib
ld: warning: directory not found for option '-L/Users/unknownn/opencv/-Wl,-rpath,/usr/local/cuda'
ld: warning: directory not found for option '-L-Wl,-rpath,/usr/local/cuda'
ld: library not found for -llib
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [lib/libopencv_cudev.4.0.1.dylib] Error 1
make[1]: *** [modules/cudev/CMakeFiles/opencv_cudev.dir/all] Error 2
make: *** [all] Error 2
I have already tried pretty much every cuda (9, 9.2, 10) and opencv (3.4, 4.0.1) version. Also I am aware that every cuda version requires a specific Xcode version.
I have also tried various cmake versions
I checked for the correct cuda paths in ccmake.
I dont know why the ld warnings appear since /usr/local/cuda exist.
What is -llib?

Answer 1

I had the same problem as well, what's interesting is that the problem does not appear to be with OpenCV, but with cmake.
The FindCUDA that comes with cmake seems to be broken, producing that strange -llib. You can see it during the cmake run as well as:
Extra dependencies: cudart_static lib nppc nppial nppicc nppicom nppidei nppif nppig nppim nppist nppisu nppitc npps cublas cufft -L/usr/local/cuda/lib -L-Wl,-rpath,/usr/local/cuda
(Note the second element "lib", the last two -L... elements will cause problem when you do make install as well)
However, the opencv source package comes with FindCUDA.cmake files that seem to work.
Assuming:
cmake is in /usr/local/share/cmake
opencv source is in ~/opencv
Do the following first:
mv /usr/local/share/cmake/Modules/FindCUDA* /tmp # Or some other back up location
cp -r ~/opencv/cmake/FindCUDA* /usr/local/share/cmake/Modules
Then run your build steps as before (cmake ..., make ..., make install), and hopefully it will work this time (it did for me).
As far as I can tell, cmake has deprecated FindCUDA.cmake, so I'm guessing it won't get fixed any time soon.

Answer 2

Answer by Jack Leow was very usefull, but I had to make farther investigation, because indeed his solution doesn't work any more.
Finally I have found this answer on opencv github by alalek. If in short, he proposes to add following cmake definition:
-DOPENCV_CUDA_FORCE_BUILTIN_CMAKE_MODULE=ON
This solution works to me.
P.S.: Currently I managed to solve few more issues on my way to get awesome opencv build. But currently build is in progress (44%) hope it will be finished in next half an hour, haha!

Answer 3

sorry, although this workaround worked once with opencv-3.4.9 / XCode8.2 (Clang 8) / CMake 3.12, now the switching of the FindCUDA files does not work anymore with the combination
opencv-3.4.9 / XCode9.2 (Clang 9) / CMake 3.16 with the following error:
CMake Error at /Applications/CMake.app/Contents/share/cmake3.16/Modules/FindCUDA.cmake:416 (file):
file failed to open for writing (Permission denied):
/Users/filippo/opencv- 3.4.9/modules/core/CMakeFiles/cuda_compile.dir/src/cuda/cuda_compile_genera ted_gpu_mat.cu.o.depend
Call Stack (most recent call first):
/Applications/CMake.app/Contents/share/cmake-3.16/Modules/FindCUDA.cmake:1363 (cuda_include_nvcc_dependencies)
/Applications/CMake.app/Contents/share/cmake-3.16/Modules/FindCUDA.cmake:1650 (CUDA_WRAP_SRCS)
/Applications/CMake.app/Contents/share/cmake-3.16/Modules/FindCUDA.cmake:1663 (cuda_compile_base)
cmake/OpenCVDetectCUDA.cmake:262 (CUDA_COMPILE)
cmake/OpenCVUtils.cmake:1513 (ocv_cuda_compile)
cmake/OpenCVModule.cmake:927 (ocv_add_library)
cmake/OpenCVModule.cmake:848 (_ocv_create_module)
modules/core/CMakeLists.txt:81 (ocv_create_module)
I had to update XCode to the 9.2 because I had a "nullability" compiling error in the building opencv-3.4.9 probably caused by Clang.