anchor.diff:  in
   {
     spdlog_1 = generic {
  -    version = "1.3.1";
  -    sha256 = "1rd4zmrlkcdjx0m0wpmjm1g9srj7jak6ai08qkhbn2lsn0niifzd";
  +    version = "1.4.2";
  +    sha256 = "1qc3rphvik44136ms0gjq2wmkl6qglri4fqxlhr2l5jwm8zhr8fc";
     };
   
     spdlog_0 = generic {
  
positive.code: let
    generic = { version, sha256 }:
      stdenv.mkDerivation {
        name = "spdlog-${version}";
        inherit version;
  
        src = fetchFromGitHub {
  
negative.code: 
        nativeBuildInputs = [ cmake ];
  
        cmakeFlags = [ "-DSPDLOG_BUILD_EXAMPLE=OFF" "-DSPDLOG_BUILD_BENCH=OFF" ];
  
        outputs = [ "out" "doc" ];
  
  