Took me 4 hours to figure out: gist.github.com/xlfe/7786057
Edit - Included content from link:
# Pre-requsites:
# X-code 5.0.1 with command line tools
# Homebrew, homebrew python, homebrew pip
export CFLAGS="-arch i386 -arch x86_64"
export FFLAGS="-m32 -m64"
export LDFLAGS="-Wall -undefined dynamic_lookup -bundle -arch i386 -arch x86_64"
export CC=gcc-4.2
export CXX="g++ -arch i386 -arch x86_64"
brew install gfortran
brew install apple-gcc42
pip install cython
#use existing brews
brew tap samueljohn/python
brew tap homebrew/science
pip install nose
#installs numpy as a dependency
brew install scipy
pip install scikit-learn