anchor.diff:  , git, ninja, python2 }:
   
   let
  -  rev = "96ff462cddf35f98e25fd5d098fc27bc81eab94a";
  -  sha256 = "1ny23sprl7ygb2lpdnqxv60m8kaf4h2dmpqjp61l5vc2s7f32g97";
  +  rev = "0bc16a82ea001ad9c94b870f097034be5c8e40b4";
  +  sha256 = "01as6q5xr0smiihm9m1x74pykd2jcqi4rhv8irmv43v2f0pxwzi5";
   
     shortRev = builtins.substring 0 7 rev;
     lastCommitPosition = writeText "last_commit_position.h" ''
  
positive.code:   ]);
  
    buildPhase = ''
      python build/gen.py --no-sysroot --no-last-commit-position
      ln -s ${lastCommitPosition} out/last_commit_position.h
      ninja -j $NIX_BUILD_CORES -C out gn
    '';
  
negative.code: in
  stdenv.mkDerivation rec {
    name = "gn-${version}";
    version = "20190726";
  
    src = fetchgit {
      url = "https://gn.googlesource.com/gn";
      inherit rev sha256;
    };
  
    nativeBuildInputs = [ ninja python2 git ];
    buildInputs = lib.optionals stdenv.isDarwin (with darwin; with apple_sdk.frameworks; [
  