anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "4.4";
  +      urls = tarballUrls "4.5";
         pgpsigUrls = map (n: "${n}.sig") urls;
         pgpKeyFingerprint = "155D 3FC5 00C8 3448 6D1E  EA67 7FD9 FCCB 000B EEEE";
         inherit (src) outputHashAlgo;
  -      outputHash = "cbd6ebc5aaf080ed60d0162d7f6aeae58211a1ee9ba9bb25623daa6cd942683b";
  +      outputHash = "7aad73c8839c2bdadca9476f884d2953cdace9567ecd0d90f9959f229d146b40";
       };
     };
   
  
positive.code: { stdenv
  , fetchurl
  , perl
  }:
  
  let
    version = "4.4";
  
    tarballUrls = version: [
      "mirror://gnu/sed/sed-${version}.tar.xz"
  
negative.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "7aad73c8839c2bdadca9476f884d2953cdace9567ecd0d90f9959f229d146b40";
    };
  
    nativeBuildInputs = [
      perl
    ];
  
    buildInputs = [
      acl
    ];
  
    postPatch = ''
  