anchor.diff:    inherit (stdenv.lib)
       replaceChars;
   
  -  version = "9.20";
  +  version = "9.21";
     versionNoP = replaceChars ["."] [""] version;
   
     fonts = stdenv.mkDerivation {
  
positive.code: 
    passthru = {
      inherit version fonts;
    };
  
    meta = with stdenv.lib; {
  
negative.code:     '';
    };
  
    baseUrl = "https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs${versionNoP}";
  in
  stdenv.mkDerivation rec {
    name = "ghostscript-${version}";
  
    src = fetchurl {
      url = "${baseUrl}/${name}.tar.xz";
      hashOutput = false;
      sha256 = "2be1d014888a34187ad4bbec19ab5692cc943bd1cb14886065aeb43a3393d053";
    };
  
    outputs = [
  