anchor.diff:  
     google-cloud-go = buildFromGitHub {
       version = 3;
  -    date = "2017-05-24";
  -    rev = "c657c56d8141b4cc4f30e9a68537cd4a8cf5b278";
  +    date = "2017-05-26";
  +    rev = "c941357ceed58af52fe865f4d824270c4d6b9ec5";
       owner = "GoogleCloudPlatform";
       repo = "google-cloud-go";
  -    sha256 = "0mhhgkzk1km5sxikbvly37yvwa3kqm0pps0cgj012bi2937hs0dl";
  +    sha256 = "1bnzsjdzayr1i4pld8jhid4c7qwpwiaq2n590dw4q1b19xdcqkdv";
       goPackagePath = "cloud.google.com/go";
       goPackageAliases = [
         "google.golang.org/cloud"
  
positive.code: 
    distribution = buildFromGitHub {
      version = 3;
      rev = "a1576d6e2165de28e0a5a0530f8e2e5c151b1ae3";
      owner = "docker";
      repo = "distribution";
      sha256 = "1gg3vdipblpii32d1plazw4m38zgazy8z3yv08rc65883m80gvkq";
      meta.useUnstable = true;
      date = "2017-05-24";
    };
  
negative.code:     version = 3;
      owner = "ncw";
      repo = "rclone";
      date = "2017-05-26";
      rev = "5455d34f8c7c287c302cee322e823680cc58753e";
      sha256 = "0d8nvbqxkd9w3c9zr13ig4fqa53lkj1bp71i6z7nc5c5qvvg4bbb";
      propagatedBuildInputs = [
        aws-sdk-go
        cobra
  