anchor.diff:  
     meta = with stdenv.lib; {
       description = "The Z command shell";
  -    homepage = "http://www.zsh.org/";
  +    homepage = http://www.zsh.org/;
       license = licenses.mit;
       maintainers = with maintainers; [
         codyopel
  
positive.code:   postInstall = ''
      mkdir -p $out/share
      tar xf ${documentation} -C $out/share
    '' +
    /* TODO: convert this to install a static file */ ''
      mkdir -p $out/etc
      cat > $out/etc/zprofile <<EOF
      if test -e /etc/NIXOS; then
  
negative.code:     enFlag
      optionals
      wtFlag;
  
    version = "5.2";
  
    documentation = fetchurl {
      url = "mirror://sourceforge/zsh/zsh-${version}-doc.tar.gz";
      sha256 = "1r9r91gmrrflzl0yq10bib9gxbqyhycb09hcx28m2g3vv9skmccj";
    };
  in
  stdenv.mkDerivation {
    name = "zsh-${version}";
  
  