anchor.diff:  
     crypto = buildFromGitHub {
       version = 2;
  -    rev = "f6b343c37ca80bfa8ea539da67a0b621f84fab1d";
  -    date = "2016-12-21";
  +    rev = "c3b1d0d6d8690eaebe3064711b026770cc37efa3";
  +    date = "2017-01-07";
       owner    = "golang";
       repo     = "crypto";
  -    sha256 = "1q8ry46xkq354szl5xf8568dvfznv21hkbbl7cigrdmmbrm82984";
  +    sha256 = "01cpr1m3v1n893nnsw0lx4r9dc00cs1nfwz68np73pq3lirc5nkg";
       goPackagePath = "golang.org/x/crypto";
       goPackageAliases = [
         "code.google.com/p/go.crypto"
  
positive.code: 
    structs = buildFromGitHub {
      version = 2;
      date = "2016-12-30";
      rev = "1de5ce037865f641d8eb22007e31cc5292a54e12";
      owner  = "fatih";
      repo   = "structs";
      sha256 = "1ki2gsv23sylbdcvi4rhgcr8cx3rg6wv84pzhj6rc6rh9kv78brg";
    };
  
    stump = buildFromGitHub {
  
negative.code: 
    httprouter = buildFromGitHub {
      version = 2;
      rev = "8a45e95fc75cb77048068a62daed98cc22fdac7c";
      owner  = "julienschmidt";
      repo   = "httprouter";
      sha256 = "1gbzzzlrqafvxv6wglam518825blwywh071p98m91wnyx36b0k7a";
      date = "2017-01-05";
    };
  
    hugo = buildFromGitHub {
  