anchor.diff:      # For more inforation, see: https://github.com/apple/swift/pull/3594#issuecomment-234169759
       clang = fetch {
         repo = "swift-clang";
  -      sha256 = "1ap26425zhn2sdw3m9snyrqhi4phv2fgblyv9wp8xppjlnjkax9k";
  +      sha256 = "046p7f4044ls8hhgklsz32md5jvxkaaim1d75n0fmnwap6di3n1q";
       };
       llvm = fetch {
         repo = "swift-llvm";
  
positive.code:     };
      foundation = fetch {
        repo = "swift-corelibs-foundation";
        sha256 = "11w0iapccrk13hjbrwylq8g71znrncnc3mrm345gvnjfgz08ffaq";
      };
      libdispatch = fetch {
        repo = "swift-corelibs-libdispatch";
        sha256 = "1mgzsq3nfzbkssfkswzvvjgsbv2fx36i1r83d4nzw3di8spxmg32";
        fetchSubmodules = true;
      };
      swift = fetch {
        repo = "swift";
        sha256 = "02bv47pd0k0xy4k7q6c3flwxwkm2palnzvpr4w3nmvqk0flrbsq6";
      };
    };
  
  
negative.code:     PREFIX=''${out/#\/}
      substituteInPlace swift-corelibs-xctest/build_script.py \
        --replace usr "$PREFIX"
    '';
  
    buildPhase = builder;
  