anchor.diff:    passthru = {
       srcVerification = fetchurl {
         failEarly = true;
  -      sha256Url = "https://download.gnome.org/sources/librsvg/${channel}/"
  -        + "${name}.sha256sum";
         inherit (src) urls outputHash outputHashAlgo;
  +      fullOpts = {
  +        sha256Url = "https://download.gnome.org/sources/librsvg/${channel}/"
  +          + "${name}.sha256sum";
  +      };
       };
     };
   
  
positive.code:   src = fetchurl {
      url = "mirror://gnome/sources/librsvg/${channel}/${name}.tar.xz";
      hashOutput = false;
      sha256 = "cff4dd3c3b78bfe99d8fcfad3b8ba1eee3289a0823c0e118d78106be6b84c92b";
    };
  
    buildInputs = [
      bzip2
      cairo
      fontconfig
      gdk-pixbuf
      glib
      gobject-introspection
  
negative.code: , fetchurl
  , lib
  
  , cairo
  , fontconfig
  , freetype
  , gdk-pixbuf
  , glib
  , gobject-introspection
  