OS X CUDA 9.0 missing nccl

I’m working on building tensorflow for Mac OS X using CUDA 9.0 and cuDNN 7.0. I have the CUDA libraries installed, but I noticed that nccl is not one of them (see directory listing below). I found source code here https://github.com/NVIDIA/nccl, but it seems to be deprecated. It directs me to http://developer.nvidia.com/nccl for a more recent download, but I don’t see an OS X option. Is there a version that is typically used with CUDA 9.0, or are the versions completely independent?

find /Developer/NVIDIA/CUDA-9.0/lib -name “*.a”

/Developer/NVIDIA/CUDA-9.0/lib/libcublas_device.a
/Developer/NVIDIA/CUDA-9.0/lib/libcublas_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libcudadevrt.a
/Developer/NVIDIA/CUDA-9.0/lib/libcudart_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libcufft_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libcufftw_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libculibos.a
/Developer/NVIDIA/CUDA-9.0/lib/libcurand_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libcusolver_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libcusparse_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppc_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppial_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppicc_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppicom_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppidei_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppif_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppig_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppim_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppist_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppisu_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnppitc_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnpps_static.a
/Developer/NVIDIA/CUDA-9.0/lib/libnvgraph_static.a