Sorry for the delayed reply …
Regarding the compiler I have:
clang --version
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin16.7.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
I tried updating with brew install llvm which installs but “keg-only”:

llvm keg-only.png2470×1718 490 KB

I am currently running again:
MACOSX_DEPLOYMENT_TARGET=10.9 CC=clang CXX=clang++ TORCH_CUDA_ARCH_LIST=6.1 python3 setup.py install
If it doesn’t work, I will python3 setup.py clean and try running again the compilation with:
export LDFLAGS="-L/usr/local/opt/llvm/lib"
export CPPFLAGS="-I/usr/local/opt/llvm/include"
I keep you updated if that works or still raises errors. Thanks !