anchor.diff:    maketar = { targets }:
       stdenv.mkDerivation {
         name = "maketar";
  +      buildInputs = [gnutar perl bzip2];
         exportReferencesGraph = map (x: [("closure-" + baseNameOf x) x]) targets;
         buildCommand = ''
  -        storePaths=$(${perl}/bin/perl ${pathsFromGraph} ./closure-*)
  +        storePaths=$(perl ${pathsFromGraph} ./closure-*)
   
  -        # printRegistration=1 ${perl}/bin/perl ${pathsFromGraph} ./closure-* > .reginfo
           tar cfj $out \
             --owner=0 --group=0 --mode=u+rw,uga+r \
             --hard-dereference \
  
positive.code:       '';
      };
  
    nix-user-chroot = stdenv.mkDerivation {
      name = "nix-user-chroot-2b144e";
      src = fetchFromGitHub {
  
negative.code:     stdenv.mkDerivation {
        name = "arx";
        buildCommand = ''
          ${haskellPackages.arx}/bin/arx tmpx ${archive} -rm! -o $out // ${startup}
          chmod +x $out
        '';
      };
  