After getting past other build issues with ArrayFire v3.3.1, I get:

CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
CUDA_CUDA_LIBRARY (ADVANCED)
    linked by target "afcuda" in directory /ufs/eyalroz/src/arrayfire-full-3.3.1/src/backend/cuda
    linked by target "write_cuda" in directory /ufs/eyalroz/src/arrayfire-full-3.3.1/test
    etc. etc.

If I add the following snippet to CMakeLists.txt:

    IF(NOT "$ENV{CUDA_CUDA_LIBRARY}" STREQUAL "")
      SET(CUDA_CUDA_LIBRARY $ENV{CUDA_CUDA_LIBRARY})
    ENDIF(NOT "$ENV{CUDA_CUDA_LIBRARY}" STREQUAL "")

and do export CUDA_CUDA_LIBRARY=/path/to/cuda/lib64/libcudart.so, then CMake happily (?) continues beyond this point. But that's not quite a solution...

PS - Sorry about filing lots of bugs on the same day... think about it as free QA on Fedora :-)