anchor.diff:    };
   
     image = buildFromGitHub {
  -    rev = "baddd3465a05d84a6d8d3507547a91cb188c81ea";
  -    date = "2015-09-16";
  +    rev = "7c492694a6443a92fd349fda0c4c7b587040f161";
  +    date = "2016-01-02";
       owner = "golang";
       repo = "image";
  -    sha256 = "0rdknh8x74ds42rdqwhix3hzm954r93xnm26qiykr7mhj9wvn098";
  +    sha256 = "05c5qrph5r5ikzxw1mlgihx8396hawv38q2syjvwbxdiib9gfg9k";
       goPackagePath = "golang.org/x/image";
       goPackageAliases = [ "github.com/golang/image" ];
     };
   
     net = buildFromGitHub {
  -    rev    = "2e9cee70ee697e0a2ef894b560dda50dec7dff58";
  -    date   = "2015-01-21";
  +    rev = "6ccd6698c634f5d835c40c1c31848729e0cecda1";
  +    date = "2016-02-02";
       owner  = "golang";
       repo   = "net";
  -    sha256 = "0063a9mqsairl62gs48x2maclka4gndakz1fqzcqsmsd7p483rxh";
  +    sha256 = "10gnjjcgzn7z9l4hyqlammilxigln4m7jriv5apcsdk81ywbjrb5";
       goPackagePath = "golang.org/x/net";
       goPackageAliases = [
         "code.google.com/p/go.net"
  
positive.code: 
  
    protobuf = buildFromGitHub {
      rev = "68415e7123da32b07eab49c96d2c4d6158360e9b";
      date = "2015-12-06";
      owner = "golang";
      repo = "protobuf";
      sha256 = "0gi2r9n7fbr7vz0rkvngnrc1y0bbk1zyqlph023s76w8d98ykxx2";
      goPackagePath = "github.com/golang/protobuf";
      goPackageAliases = [ "code.google.com/p/goprotobuf" ];
    };
  
    snappy = buildFromGitHub {
      rev    = "723cc1e459b8eea2dea4583200fd60757d40097a";
      date   = "2015-07-21";
      owner  = "golang";
      repo   = "snappy";
      sha256 = "0bprq0qb46f5511b5scrdqqzskqqi2z8b4yh3216rv0n1crx536h";
      goPackageAliases = [ "code.google.com/p/snappy-go/snappy" ];
    };
  
    sys = buildFromGitHub {
      rev    = "833a04a10549a95dc34458c195cbad61bbb6cb4d";
      date   = "2015-12-10";
      owner  = "golang";
      repo   = "sys";
      sha256 = "0lfam5kj2jl54cmkgr155mgidxgsxph3cyvw1zi0rbdkaj58crp1";
      goPackagePath = "golang.org/x/sys";
      goPackageAliases = [
        "github.com/golang/sys"
  
negative.code:   };
  
    crypto = buildFromGitHub {
      rev = "1f22c0103821b9390939b6776727195525381532";
      date = "2016-01-26";
      owner    = "golang";
      repo     = "crypto";
      sha256 = "1acy12f396sr3lrnbcnym5q72qnlign5bagving41qijzjnc219m";
      goPackagePath = "golang.org/x/crypto";
      goPackageAliases = [
        "code.google.com/p/go.crypto"
  