Error trying to install GPU for OSX on local computer

I have followed the steps on the PyTorch github page for macOS Sierra, and I got the error on the last step using MACOSX_DEPLOYMENT_TARGET=10.9 CC=clang CXX=clang++ python setup.py install . the Error look like this

error “The CMAKE_C_COMPILER is set to a C++ compiler”

Please help me. Thanks !