anchor.diff:  
     hcl = buildFromGitHub {
       version = 2;
  -    date = "2016-10-28";
  -    rev = "8fa153c5b4e9d1ccecda7075821ffc7c1f6d912b";
  +    date = "2016-11-01";
  +    rev = "6e968a3fcdcbab092f5307fd0d85479d5af1e4dc";
       owner  = "hashicorp";
       repo   = "hcl";
  -    sha256 = "12rjwb8yzc6mk9l00xf3nmhijkvc7nxjw5bdp9d6ii8yp6karg22";
  +    sha256 = "1g5xmr9y94rns8dy0wsqg2z4w3nfblln4vpm9fipbp9xy9w9gdh7";
     };
   
     hdrhistogram = buildFromGitHub {
  
positive.code: 
    tools = buildFromGitHub {
      version = 2;
      rev = "b814a3b030588c115189743d7da79bce8b549ce1";
      date = "2016-10-28";
      owner = "golang";
      repo = "tools";
      sha256 = "0bvs1cwa22wxbr09pg2yvsr4sn589pzgjdf49wavw9rf95n33j3i";
      goPackagePath = "golang.org/x/tools";
      goPackageAliases = [ "code.google.com/p/go.tools" ];
  
  
negative.code: 
    net = buildFromGitHub {
      version = 2;
      rev = "4bb47a1098b37d69980d96237e2ae4ff56bb5a95";
      date = "2016-10-31";
      owner  = "golang";
      repo   = "net";
      sha256 = "0v0x19f6ppvdd5kz41sjq0gq620rd12aha06xa86rsydl7018f6g";
      goPackagePath = "golang.org/x/net";
      goPackageAliases = [
        "github.com/hashicorp/go.net"
  