anchor.diff:      "--with-readline"
     ];
   
  -  postConfigure =
  -    /* Don't regen docs -- configure produces a small fragment
  -       that includes the version info which causes all pages to
  -       regen (newer file). */ ''
  -    	touch -r doc doc/*
  -    '';
  +  # Prevent doc rebuild
  +  preBuild = ''
  +    touch doc doc/*
  +  '';
   
  -  postBuild =
  -    /* Simple test */ ''
  -      echo "quit" | ./bc/bc -l Test/checklib.b
  -    '';
  +  doCheck =true;
   
  -  doCheck = true;
  +  passthru = {
  +    srcVerification = fetchurl {
  +      failEarly = true;
  +      pgpsigUrls = map (n: "${n}.sig") src.urls;
  +      pgpKeyFingerprint = "00E4 2623 2F38 4BF6 D32D  8B18 81C2 4FF1 2FB7 B14B";
  +      inherit (src) urls outputHash outputHashAlgo;
  +    };
  +  };
   
     meta = with stdenv.lib; {
       description = "GNU software calculator";
  
positive.code: { stdenv
  , bison
  , fetchTritonPatch
  , fetchurl
  , flex
  
  
negative.code: }:
  
  stdenv.mkDerivation rec {
    name = "bc-1.07";
  
    src = fetchurl {
      url = "mirror://gnu/bc/${name}.tar.gz";
      hashOutput = false;
      sha256 = "55cf1fc33a728d7c3d386cc7b0cb556eb5bacf8e0cb5a3fcca7f109fc61205ad";
    };
  
    nativeBuildInputs = [
      ed
      flex
    ];
  
    buildInputs = [
      flex
      ncurses
      readline
    ];
  
    configureFlags = [
  