anchor.diff:  
     consul = buildFromGitHub rec {
       version = 2;
  -    rev = "v0.7.3";
  +    rev = "v0.7.4";
       owner = "hashicorp";
       repo = "consul";
  -    sha256 = "175c2xxm09cy2784x385djazvxnlh4a4yv872mmlgyb27f3c95q1";
  +    sha256 = "0xprbgkqizzxhpp3a9jg4gh47mfb4g6w7zfbwhhwscbni8hll95h";
   
       buildInputs = [
         datadog-go circbuf armon_go-metrics go-radix speakeasy bolt
  
positive.code: 
    go-multihash = buildFromGitHub {
      version = 2;
      rev = "6becc51c635d43eb3ab4783e1e4777c7f0e6e785";
      owner  = "multiformats";
      repo   = "go-multihash";
      sha256 = "1d6xgjwxjiw5ggplskd2hxz32h3s7akf2cls3ahzk0fgkww15ycv";
      goPackageAliases = [ "github.com/jbenet/go-multihash" ];
      propagatedBuildInputs = [
        crypto
        go-base58
      ];
      date = "2017-01-06";
    };
  
    go-multipart-files = buildFromGitHub {
  
negative.code: 
    log15 = buildFromGitHub {
      version = 2;
      rev = "1e7b2e232399d12bd3e50dc9d182df4e18258355";
      owner  = "inconshreveable";
      repo   = "log15";
      sha256 = "1rwyky7liawadgrad9j7pqhv0acja8c43kza7k96pr0j4vqwjjp6";
      propagatedBuildInputs = [
        go-colorable
        stack
      ];
      date = "2017-02-06";
    };
  
    log15_v2 = buildFromGitHub {
  