anchor.diff:  , asciidoc, docbook_xml_dtd_45, docbook_xsl, libxml2, libxslt
   , coreutils, gawk, gnugrep, gnused, jq, nix }:
   
  -with stdenv.lib;
  -
   stdenv.mkDerivation rec {
     pname = "nix-prefetch";
  -  version = "0.1.0";
  +  version = "0.3.0";
   
     src = fetchFromGitHub {
       owner = "msteen";
       repo = "nix-prefetch";
  -    rev = "f9507a655651b51f3a3ebacde85bb40758853615";
  -    sha256 = "0ykrbvbwwpz348424yy2452idgw8dffi3klh7n85n96dfflyyd4s";
  +    rev = version;
  +    sha256 = "0b9gdi7xzmfq0j258x724xsll8gi31m0m4pzfjkqinlm6zwr3sgm";
     };
   
     nativeBuildInputs = [
  
positive.code:     install -D contrib/nix-prefetch-completion.bash $out/share/bash-completion/completions/nix-prefetch
      install -D contrib/nix-prefetch-completion.zsh $out/share/zsh/site-functions/_nix_prefetch
  
      mkdir $out/contrib
      cp -r contrib/hello_rs $out/contrib/
    '';
  
    meta = {
      description = "Prefetch any fetcher function call, e.g. package sources";
      homepage = https://github.com/msteen/nix-prefetch;
      license = licenses.mit;
      maintainers = with maintainers; [ msteen ];
      platforms = platforms.all;
  
negative.code: 
      mkdir -p $out/bin
      makeWrapper $lib/main.sh $out/bin/${pname} \
        --prefix PATH : '${stdenv.lib.makeBinPath [ coreutils gawk gnugrep gnused jq nix ]}'
  
      substitute src/tests.sh $lib/tests.sh \
        --subst-var-by bin $out/bin
  