anchor.diff:  
     gojsonschema = buildFromGitHub {
       version = 2;
  -    rev = "f06f290571ce81ab347174c6f7ad2e1865af41a7";
  +    rev = "6b67b3fab74d992bd07f72550006ab2c6907c416";
       owner  = "xeipuuv";
       repo   = "gojsonschema";
  -    sha256 = "1c1rdiyz2liynjffavhm0zah2488qcc34hdv5rlmygsqxyq0wxzj";
  -    date = "2016-12-31";
  +    sha256 = "05simcc7wvhdhg8diy919x8s9mx92sqbipq0vh7ikvdam88kfj7c";
  +    date = "2017-02-11";
       propagatedBuildInputs = [ gojsonreference ];
     };
   
  
positive.code: 
    macaron_v1 = buildFromGitHub {
      version = 2;
      rev = "v1.2.0";
      owner  = "go-macaron";
      repo   = "macaron";
      sha256 = "0yzdabmc4dkqzx1r4grivimrxi5w9nwiwfmfrk145i1cydgfckw9";
      goPackagePath = "gopkg.in/macaron.v1";
      goPackageAliases = [
        "github.com/go-macaron/macaron"
  
negative.code: 
    consul = buildFromGitHub rec {
      version = 2;
      rev = "v0.7.5";
      owner = "hashicorp";
      repo = "consul";
      sha256 = "1czz99gf1wgml9iiy8aw6z0glihwzvpq86fzdwn6awkchhw8rh5j";
  
      buildInputs = [
        datadog-go circbuf armon_go-metrics go-radix speakeasy bolt
  