anchor.diff:  
     sys = buildFromGitHub {
       version = 2;
  -    rev = "aaabbdc969c3935a2a7f61efac801e7163c73a2a";
  +    rev = "e24f485414aeafb646f6fca458b0bf869c0880a1";
       date = "2017-02-10";
       owner  = "golang";
       repo   = "sys";
  -    sha256 = "13ryidi102rksybvz30d58qn22jjdx9m1nmqz2c03c9vvb49m9cx";
  +    sha256 = "0cc213v5jyxn773wdmanqzd08qhy14a890314x1hivcs6ysrw7iv";
       goPackagePath = "golang.org/x/sys";
       goPackageAliases = [
         "github.com/golang/sys"
  
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: 
    go-memdb = buildFromGitHub {
      version = 2;
      date = "2017-02-10";
      rev = "6b158e314030abfb0dbbbc24d0ac71b132259ebf";
      owner = "hashicorp";
      repo = "go-memdb";
      sha256 = "087a6a73x69pvy6bk9krw3v8a67xyg8brvz8jvsvj1g247xnqk4d";
      propagatedBuildInputs = [
        go-immutable-radix
      ];
  