anchor.diff:    };
   
     tools = buildFromGitHub {
  -    version = 2;
  -    rev = "9a6c6fca12efdd355f948c5b748b8b48edbb4ef0";
  -    date = "2017-04-26";
  +    version = 3;
  +    rev = "2382e3994d48b1d22acc2c86bcad0a2aff028e32";
  +    date = "2017-04-28";
       owner = "golang";
       repo = "tools";
  -    sha256 = "087bv7ll4kx8amcgzx3w6vjq6w0mzllzvqx74zxpa9w4x6iyigzz";
  +    sha256 = "1i8rfq2l6vfdsj358k9fran2h1cc4dr28kncv17s4gw5w9zd9iya";
       goPackagePath = "golang.org/x/tools";
       goPackageAliases = [ "code.google.com/p/go.tools" ];
   
  
positive.code:   };
  
    google-cloud-go = buildFromGitHub {
      version = 2;
      date = "2017-04-24";
      rev = "3536fc15a6517d90ba50b7ca76ddcb404e8ff1f3";
      owner = "GoogleCloudPlatform";
      repo = "google-cloud-go";
      sha256 = "19q7kqw1fpzmmz6733nqwhl8m3bjw8w5952jdfry52svq6srdgbs";
      goPackagePath = "cloud.google.com/go";
      goPackageAliases = [
        "google.golang.org/cloud"
  
negative.code:   };
  
    grpc = buildFromGitHub {
      version = 3;
      date = "2017-04-27";
      rev = "277e90a4321cba6ad9f9ca4a832165265002c3a5";
      owner = "grpc";
      repo = "grpc-go";
      sha256 = "18x55b85w5v05h3772b9ls630dcwhz7kksgdh78zhm70axan06dx";
      goPackagePath = "google.golang.org/grpc";
      goPackageAliases = [
        "github.com/grpc/grpc-go"
  