anchor.diff:                  (builtins.attrValues installRequirements.packages);
       ignoreCollisions = true;
     };
  -  envVars = ''
  -    export PYTHONPATH=./src:../more.babel_i18n:../more.browser_session:${python}/${python.sitePackages}
  -    export GIT_SSL_CAINFO="${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"; 
  -  '';
   
   in pkgs.mkShell {
     name = "ekklesia_portal-dev-env";
  
positive.code:     werkzeug
    ]) 
    ;
    shellHook = envVars + (lib.optionalString 
                           usePipenvShell "SHELL=`which zsh` exec pipenv shell --fancy");
  }
  
negative.code: { sources ? import ./nix/sources.nix }:
  let
    pkgs = import sources.nixpkgs { };
    niv = (import sources.niv { }).niv;
  