anchor.diff:      version = 3;
       owner = "AudriusButkevicius";
       repo = "kcp-go";
  -    rev = "02298ef4d96d48912e016f5fb36dcc0cd93c257f";
  -    sha256 = "0w6lp8m5w9vyzmqzfa32ciq9dlyncn87z49ci19ymdbhs4s8qmhf";
  +    rev = "81872260d8e9a51c0fa1d5206534e5a3064e7dc4";
  +    sha256 = "1dh1mzjk25fp7lkmyg64q5igycisvhcc2rmi2smb4a2h2s3i20mm";
       propagatedBuildInputs = [
         crypto
         errors
  
positive.code: 
    appengine = buildFromGitHub {
      version = 3;
      rev = "07f075729064fd38e1360517947f0f6e03500651";
      owner = "golang";
      repo = "appengine";
      sha256 = "1f8zj529hh46hypn8bl8ym66rm2dx1fxzxivmj1r1vfgwxb7ywzb";
      goPackagePath = "google.golang.org/appengine";
      excludedPackages = "aetest";
      propagatedBuildInputs = [
  
negative.code: 
    hcl = buildFromGitHub {
      version = 3;
      date = "2017-10-17";
      rev = "23c074d0eceb2b8a5bfdbb271ab780cde70f05a8";
      owner  = "hashicorp";
      repo   = "hcl";
      sha256 = "1ri7hdbsq574j8ii81rn92l3fyqg7f5i6xxqmdzxs6iclmydf1zm";
    };
  
    hdrhistogram = buildFromGitHub {
  