anchor.diff:    passthru = {
       srcVerification = fetchurl rec {
         failEarly = true;
  -      urls = tarballUrls "2.2.4";
  -      pgpsigUrls = map (n: "${n}.sig") urls;
  -      pgpKeyFingerprints = [
  -        "FF47 8FB2 64DE 32EC 2967  25A3 DDC0 F535 8812 F8F2"
  -        "3CE4 6455 8A84 FDC6 9DB4  0CFB 090B 1199 3D9A EBB5"
  -        "4FD4 D288 D445 934E 0A14  F9A5 A880 3732 E443 6885"
  -      ];
  +      urls = tarballUrls "2.2.6";
         inherit (src) outputHashAlgo;
  -      outputHash = "d9e8b94af7b206fcf52bec6501b921bd7d0bd7a31fb7e896a35ba8253678e31e";
  +      outputHash = "b33576331465a60b003573541bf3b1c205936a16c407bc69f8419a527bf5c988";
  +      fullOpts = {
  +        pgpsigUrls = map (n: "${n}.sig") urls;
  +        pgpKeyFingerprints = [
  +          "FF47 8FB2 64DE 32EC 2967  25A3 DDC0 F535 8812 F8F2"
  +          "3CE4 6455 8A84 FDC6 9DB4  0CFB 090B 1199 3D9A EBB5"
  +          "4FD4 D288 D445 934E 0A14  F9A5 A880 3732 E443 6885"
  +        ];
  +      };
       };
     };
   
  
positive.code: }:
  
  let
    version = "2.2.4";
  
    tarballUrls = version: [
      "mirror://gnu/guile/guile-${version}.tar.xz"
  
negative.code:   src = fetchurl {
      urls = tarballUrls version;
      hashOutput = false;
      sha256 = "b33576331465a60b003573541bf3b1c205936a16c407bc69f8419a527bf5c988";
    };
  
    nativeBuildInputs = [
  