anchor.diff:  { lib
   , stdenv
   , fetchzip
  -, buildDocs? false, tex
  +, buildDocs ? false, tex
   }:
   
   stdenv.mkDerivation rec {
  
positive.code:     substituteAll ${./Makefile-nixos.def} Makefile.def
      mkdir -p .objdir
    '';
  
    hardenedDisable = [ "all" ];
  
    # buildTargets = [ "binaries" "docs" ];
  
    meta = with lib; {
      homepage = "http://john.ccac.rwth-aachen.de:8000/as/index.html";
  
negative.code:     hash = "sha256-Sbm16JX7kC/7Ws7YgNBUXNqOCl6u+RXgfNjTODhCzSM=";
    };
  
    nativeBuildInputs = lib.optionals buildDocs [ tex ];
  
    postPatch = lib.optionalString (!buildDocs) ''
      substituteInPlace Makefile --replace "all: binaries docs" "all: binaries"
  