anchor.diff:    };
   
     logrus = buildFromGitHub rec {
  -    date = "2015-12-04";
  -    rev = "446d1c146faa8ed3f4218f056fcd165f6bcfda81";
  +    rev = "v0.9.0";
       owner = "Sirupsen";
       repo = "logrus";
  -    sha256 = "0v5k2rbjni4wrwwsjdms6lyz318m6av7mp7j701i8kllnv0vk7q8";
  +    sha256 = "1m6vvd4pg4lwglhk54lv5mf6cc8h7bi0d9zb3gar4crz531r66y4";
     };
   
     logutils = buildFromGitHub {
  
positive.code:   };
  
    hcl = buildFromGitHub {
      date   = "2015-12-01";
      rev    = "c40ec20b1285f01e9e75ec39f2bf2cff132891d3";
      owner  = "hashicorp";
      repo   = "hcl";
      sha256 = "08wkhvwcxglbq9h8bavrrg71f4jyrxxd37yfs9vic4nhwhh27j4p";
    };
  
    hcl-old = buildFromGitHub {
  
negative.code:   };
  
    serf = buildFromGitHub {
      rev = "v0.7.0";
      owner  = "hashicorp";
      repo   = "serf";
      sha256 = "1zj2s29qjcaai2w03ak3rxidcmgi3mfp94f5nrmkblm44mc6667r";
  
      buildInputs = [
        net circbuf armon_go-metrics ugorji_go go-syslog logutils mdns memberlist
  