anchor.diff:  
   
     tools = buildGoPackage rec {
  -    rev = "140fcaadc5860b1a014ec69fdeec807fe3b787e8";
  -    name = "go.tools-${stdenv.lib.strings.substring 0 7 rev}";
  -    goPackagePath = "code.google.com/p/go.tools";
  -    src = fetchhg {
  -      inherit rev;
  -      url = "http://code.google.com/p/go.tools";
  -      sha256 = "1vgz4kxy0p56qh6pfbs2c68156hakgx4cmrci9jbg7lnrdaz4y56";
  -    };
  -    subPackages = [ "go/vcs" ];
  +    rev = "7d75e8b219c3efda2d08ae38acd6b42f8da4f5f9";
  +    name = "tools-${stdenv.lib.strings.substring 0 7 rev}";
  +    goPackagePath = "golang.org/x/tools";
  +
  +    src = fetchFromGitHub {
  +      inherit rev;
  +      owner = "golang";
  +      repo = "tools";
  +      sha256 = "0vq0l3pjhgsp97v6ndlr3jcs029r5zilwai30snwfq74s580sriq";
  +    };
     };
   
     ## THIRD PARTY
  
positive.code: 
  
    protobuf = buildGoPackage rec {
      rev = "efd7476481382c195beb33acd8ec2f1527167fb4";
      name = "goprotobuf-${stdenv.lib.strings.substring 0 7 rev}";
      goPackagePath = "github.com/golang/protobuf";
      goPackageAliases = [ "code.google.com/p/goprotobuf" ];
  
  
negative.code: 
    crypto = buildGoPackage rec {
      rev = "4d48e5fa3d62b5e6e71260571bf76c767198ca02";
      name = "crypto-${stdenv.lib.strings.substring 0 7 rev}";
      goPackagePath = "golang.org/x/crypto";
      goPackageAliases = [ "code.google.com/p/go.crypto" ];
      disabled = isGo13;
  