anchor.diff:      homepage = "http://gittup.org/tup/";
       license = licenses.gpl2;
       maintainers = with maintainers; [ ehmry ];
  -    platforms = platforms.linux ++ platforms.darwin;
  +    platforms = platforms.unix;
  +
  +    # TODO: Remove once nixpkgs uses newer SDKs that supports '*at' functions.
  +    # Probably MacOS SDK 10.13 or later. Check the current version in
  +    # ../../../../os-specific/darwin/apple-sdk/default.nix
  +    #
  +    # https://github.com/gittup/tup/commit/3697c74
  +    broken = stdenv.isDarwin;
     };
   }
  
positive.code:   };
  
    nativeBuildInputs = [ pkg-config ];
    buildInputs = [ fuse3 pcre ];
  
    configurePhase = ''
      sed -i 's/`git describe`/v${version}/g' src/tup/link.sh
  
negative.code: { lib, stdenv, fetchFromGitHub, fuse3, macfuse-stubs, pkg-config, pcre }:
  
  let
    fuse = if stdenv.isDarwin then macfuse-stubs else fuse3;
  in stdenv.mkDerivation rec {
    pname = "tup";
    version = "0.7.10";
    outputs = [ "bin" "man" "out" ];
  