anchor.diff:  }:
   
   let
  -  version = "2.9.9";
  +  version = "2.9.10";
   
     tarballUrls = version: [
       "http://xmlsoft.org/sources/libxml2-${version}.tar.gz"
  
positive.code: 
    src = fetchurl {
      urls = tarballUrls version;
      multihash = "QmZW6enUX5jA8JNCK72oQnCiaG4FEPuCHoC84yg12WyDqA";
      hashOutput = false;
      sha256 = "94fb70890143e3c6549f265cee93ec064c80a84c42ad0f23e85ee1fd6540a871";
    };
  
    buildInputs = [
  
negative.code:     zlib
    ];
  
    postPatch = ''
      find . -name Makefile.in -exec sed -i '/^SUBDIRS /s, \(doc\|example\),,g' {} \;
    '';
  
    configureFlags = [
      "--with-history"
      "--with-icu"
      "--with-readline=${readline}"
    ];
  
    postInstall = ''
      mkdir -p "$bin"/bin
      mv -v "$dev"/bin/* "$bin"/bin
      mv -v "$bin"/bin/*-config "$dev"/bin
  
      mkdir -p "$lib"/lib
      mv -v "$dev"/lib*/*.so* "$lib"/lib
      ln -sv "$lib"/lib/* "$dev"/lib
  
      mkdir -p "$dev"/nix-support "$bin"/nix-support
      echo '${icu}' >"$dev"/nix-support/propagated-native-build-inputs
      echo '${findXMLCatalogs}' >"$bin"/nix-support/propagated-native-build-inputs
    '';
  
    postFixup = ''
      mkdir -p "$dev"/share2
      mv -v "$dev"/share/aclocal "$dev"/share2
      rm -rv "$dev"/share
      mv "$dev"/share2 "$dev"/share
    '';
  
    outputs = [
      "dev"
      "bin"
      "lib"
      "man"
    ];
  
    passthru = {
      inherit version;
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "2.9.10";
        inherit (src) outputHashAlgo;
        outputHash = "aafee193ffb8fe0c82d4afef6ef91972cbaf5feea100edc2f262750611b4be1f";
        fullOpts = {
          pgpsigUrls = map (n: "${n}.asc") urls;
          pgpKeyFingerprint = "C744 15BA 7C9C 7F78 F02E  1DC3 4606 B8A5 DE95 BC1F";
  