anchor.diff:      };
       swift = fetch {
         repo = "swift";
  -      sha256 = "0y277wi0m6zp1yph9s14mmc65m21q5fm6lgzkn2rkrbaz25fdzak";
  +      sha256 = "1hwi6hi9ss1kj1s65v5q8v8d872c0914qfy1018xijd029lwq694";
       };
     };
   
  
positive.code: }:
  
  let
    v_base = "4.2.1";
    version = "${v_base}-RELEASE";
    version_friendly = "${v_base}";
  
  
negative.code:     };
      foundation = fetch {
        repo = "swift-corelibs-foundation";
        sha256 = "1ki9vc723r13zgm6bcmif43aypavb2hz299gbhp93qkndz8hqkx5";
      };
      libdispatch = fetch {
        repo = "swift-corelibs-libdispatch";
  