anchor.diff:  
     prometheus = buildFromGitHub {
       version = 6;
  -    rev = "v2.5.0";
  +    rev = "v2.7.1";
       owner  = "prometheus";
       repo   = "prometheus";
  -    sha256 = "javkNmjmilbj57OYscDPbX4Q656Z1nM1Afc6PGRjmZs=";
  +    sha256 = "021aab815cf1ff1f3cbcc37a2f81797e99d20a1f7d9291edd0fab672412bba5e";
       buildInputs = [
         aws-sdk-go
         cockroach
  
positive.code: 
    sys = buildFromGitHub {
      version = 6;
      rev = "b90733256f2e882e81d52f9126de08df5615afd9";
      date = "2019-01-24";
      owner  = "golang";
      repo   = "sys";
      sha256 = "ee04ffba342ccff143cfaa4564980c02d483b811ac5665b7f36c7d2d54b96c96";
      goPackagePath = "golang.org/x/sys";
    };
  
  
negative.code: 
    go-getter = buildFromGitHub {
      version = 6;
      rev = "v1.0.1";
      owner = "hashicorp";
      repo = "go-getter";
      sha256 = "16469e3b059a1ce23532bcbe14f96936765899c75a21c90ff6045d6848d2eb26";
      propagatedBuildInputs = [
        aws-sdk-go
        go-cleanhttp
  