ah got it. i installed CUDA toolkit 10.1. one problem was my environmental variable wasnt set to the cuda install directory. still doesnt build properly after fixing that however. here is the output:
(v1.1) pkg> build CuArrays
Building SpecialFunctions → `~/.julia/packages/SpecialFunctions/fvheQ/deps/build.log`
Building CUDAdrv ─────────→ `~/.julia/packages/CUDAdrv/lu32K/deps/build.log`
┌ Error: Error building `CUDAdrv`:
│ ┌ Debug: Request to look for binary nvcc
│ │ locations = 0-element Array{String,1}
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Looking for binary nvcc
│ │ locations =
│ │ 8-element Array{String,1}:
│ │ "/Users/Galen/.cargo/bin"
│ │ "/Developer/NVIDIA/CUDA-10.1/bin"
│ │ "/usr/local/bin"
│ │ "/usr/bin"
│ │ "/bin"
│ │ "/usr/sbin"
│ │ "/sbin"
│ │ "/Library/TeX/texbin"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Found binary nvcc at /Developer/NVIDIA/CUDA-10.1/bin
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/discovery.jl:142
│ ┌ Debug: Looking for CUDA toolkit via nvcc binary
│ │ path = "/Developer/NVIDIA/CUDA-10.1/bin/nvcc"
│ │ dir = "/Developer/NVIDIA/CUDA-10.1"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Request to look for library cudart
│ │ locations = 0-element Array{String,1}
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Looking for library libcudart.dylib, libcudart.dylib.10, libcudart.dylib.10.1, libcudart.dylib.10.0, libcudart.dylib.9, libcudart.dylib.9.2, libcudart.dylib.9.1, libcudart.dylib.9.0, libcudart.dylib.8, libcudart.dylib.8.0, libcudart.dylib.7, libcudart.dylib.7.5, libcudart.dylib.7.0, libcudart.dylib.6, libcudart.dylib.6.5, libcudart.dylib.6.0, libcudart.dylib.5, libcudart.dylib.5.5, libcudart.dylib.5.0, libcudart.dylib.4, libcudart.dylib.4.2, libcudart.dylib.4.1, libcudart.dylib.4.0, libcudart.dylib.3, libcudart.dylib.3.2, libcudart.dylib.3.1, libcudart.dylib.3.0, libcudart.dylib.2, libcudart.dylib.2.2, libcudart.dylib.2.1, libcudart.dylib.2.0, libcudart.dylib.1, libcudart.dylib.1.1, libcudart.dylib.1.0
│ │ locations = 0-element Array{String,1}
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Found library libcudart.dylib at /Developer/NVIDIA/CUDA-10.1/lib/libcudart.dylib
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/discovery.jl:91
│ ┌ Debug: Looking for CUDA toolkit via CUDA runtime library
│ │ path = "/Developer/NVIDIA/CUDA-10.1/lib/libcudart.dylib"
│ │ dir = "/Developer/NVIDIA/CUDA-10.1"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Looking for CUDA toolkit via default installation directories
│ │ dirs =
│ │ 1-element Array{Any,1}:
│ │ "/usr/local/cuda"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Found CUDA toolkit at /Developer/NVIDIA/CUDA-10.1, /usr/local/cuda
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/discovery.jl:271
│ ┌ Debug: Request to look for library cuda
│ │ locations =
│ │ 2-element Array{String,1}:
│ │ "/Developer/NVIDIA/CUDA-10.1"
│ │ "/usr/local/cuda"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Looking for library libcuda.dylib, libcuda.dylib.10, libcuda.dylib.10.1, libcuda.dylib.10.0, libcuda.dylib.9, libcuda.dylib.9.2, libcuda.dylib.9.1, libcuda.dylib.9.0, libcuda.dylib.8, libcuda.dylib.8.0, libcuda.dylib.7, libcuda.dylib.7.5, libcuda.dylib.7.0, libcuda.dylib.6, libcuda.dylib.6.5, libcuda.dylib.6.0, libcuda.dylib.5, libcuda.dylib.5.5, libcuda.dylib.5.0, libcuda.dylib.4, libcuda.dylib.4.2, libcuda.dylib.4.1, libcuda.dylib.4.0, libcuda.dylib.3, libcuda.dylib.3.2, libcuda.dylib.3.1, libcuda.dylib.3.0, libcuda.dylib.2, libcuda.dylib.2.2, libcuda.dylib.2.1, libcuda.dylib.2.0, libcuda.dylib.1, libcuda.dylib.1.1, libcuda.dylib.1.0
│ │ locations =
│ │ 6-element Array{String,1}:
│ │ "/Developer/NVIDIA/CUDA-10.1"
│ │ "/Developer/NVIDIA/CUDA-10.1/lib"
│ │ "/Developer/NVIDIA/CUDA-10.1/lib64"
│ │ "/usr/local/cuda"
│ │ "/usr/local/cuda/lib"
│ │ "/usr/local/cuda/lib64"
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/CUDAapi.jl:8
│ ┌ Debug: Found library /usr/local/cuda/lib/libcuda.dylib at /usr/local/cuda/lib/libcuda.dylib
│ └ @ CUDAapi ~/.julia/packages/CUDAapi/0Ozyy/src/discovery.jl:91
│ Initializing CUDA driver failed with code 3..
└ @ Pkg.Operations /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Operations.jl:1075
Building LLVM ────────────→ `~/.julia/packages/LLVM/tg8MX/deps/build.log`
Building CUDAnative ──────→ `~/.julia/packages/CUDAnative/PFgO3/deps/build.log`
┌ Error: Error building `CUDAnative`:
│ Dependent package CUDAdrv.jl has not been built successfully.
│
│ This is not a fatal error, but GPU functionality will be unavailable.
│ If you expected this to work, please open a thread on
│ https://discourse.julialang.org/c/domain/gpu
└ @ Pkg.Operations /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Operations.jl:1075
Building Conda ───────────→ `~/.julia/packages/Conda/CpuvI/deps/build.log`
Building FFTW ────────────→ `~/.julia/packages/FFTW/p7sLQ/deps/build.log`
Building CuArrays ────────→ `~/.julia/packages/CuArrays/qZCAt/deps/build.log`
┌ Error: Error building `CuArrays`:
│ Dependent package CUDAdrv.jl has not been built successfully
└ @ Pkg.Operations /Users/osx/buildbot/slave/package_osx64/build/usr/share/julia/stdlib/v1.1/Pkg/src/Operations.jl:1075