default.nix

let pkgs = import <nixpkgs> {};                                                                          
in pkgs.mkShell {                                                                                         
  buildInputs = [
    pkgs.pythonPackages.pip
  ];
  propagatedBuildInputs = [
    pkgs.libffi
    pkgs.openssl
  ];
  shellHook = ''                                                                                                                                                                                                     
            alias pip="PIP_PREFIX='$(pwd)/_build/pip_packages' \pip"                                                                                                                                                 
            export PYTHONPATH="$(pwd)/_build/pip_packages/lib/python2.7/site-packages:$PYTHONPATH"                                                                                                                   
            export PATH="$(pwd)/_build/pip_packages/bin:$PATH"                                                                                                                                                       
            unset SOURCE_DATE_EPOCH                                                                                                                                                                                  
  '';
}