anchor.diff:  
     docker = buildFromGitHub {
       version = 2;
  -    rev = "b8e9250b59de8619b94f7532c0fc182913028f1e";
  +    rev = "0e9148b1e92dc6cf79dc57c71423297d5c11d0ca";
       owner = "docker";
       repo = "docker";
  -    sha256 = "15h42yv69xrbhwyi0wrrs4fjm3jx3jpq4dr8y57qmnzlzazg38q7";
  +    sha256 = "1lqnpgqqyic6qq5ha9avlcpzbgl8v0359xym4l2fi7f5kjifpw7v";
       meta.useUnstable = true;
  -    date = "2017-04-20";
  +    date = "2017-04-21";
       propagatedBuildInputs = [
         distribution_for_docker
         errors
  
positive.code: 
    tools = buildFromGitHub {
      version = 2;
      rev = "663269851cdddc898f963782f74ea574bcd5c814";
      date = "2017-04-16";
      owner = "golang";
      repo = "tools";
      sha256 = "1wfvlx4k71cfxdhj54jj1xfrsfnbvbjwsrny9cagm17f048rqnsy";
      goPackagePath = "golang.org/x/tools";
      goPackageAliases = [ "code.google.com/p/go.tools" ];
  
  
negative.code:     version = 2;
      owner = "coreos";
      repo = "etcd";
      date = "2017-04-21";
      rev = "a9087ee659e58f26de72c4809ddabd8f58b4a97a";
      sha256 = "1qjm9blr6lhbbaxwrahb434a4s6kjda1c8c1p1s8nqj2hlz6jsm4";
      buildInputs = [
        bolt
        btree
  