Install Nix on Mac OS X 10.10 (Yosemite)

install-nix.sh

# current as of 2014-12-20
# mostly derived from https://nixos.org/wiki/Nix_on_OS_X#Using_the_Testing_Branch

curl https://nixos.org/nix/install | sh
NIXDIR=~/nixtest # or wherever you like
mkdir -p $NIXDIR
cd $NIXDIR
git clone https://github.com/joelteon/nixpkgs.git # this is the yosemite branch
nix-channel --remove nixpkgs
cd ~/.nix-defexpr
rm -rf *
ln -s "$NIXDIR/nixpkgs" .

echo "export NIX_PATH=$NIXDIR/nixpkgs:nixpkgs=$NIXDIR/nixpkgs" >> ~/.bashrc 

# create nix configuration dir and add the cache for nixpkgs

sudo mkdir /etc/nix
echo "binary-caches = http://zalora-public-nix-cache.s3-website-ap-southeast-1.amazonaws.com/ http://cache.nixos.org/" | sudo tee /etc/nix/nix.conf

# restart your shell
# and finally:
#   nix-env -i nix