anchor.diff:  
     net = buildFromGitHub {
       version = 2;
  -    rev = "5602c733f70afc6dcec6766be0d5034d4c4f14de";
  -    date = "2017-04-13";
  +    rev = "0b588ed7a0cd59c271d128ec8c429c1c1607e8ab";
  +    date = "2017-04-21";
       owner  = "golang";
       repo   = "net";
  -    sha256 = "1snnsz6gq13ys6cn09c8czcpr33j3jna6pzmd60j2b024j8q9bs7";
  +    sha256 = "1fl15zfzx8nhxr0901q8fmari6q6sg6wjmn7mqq3sxz54n2g98iw";
       goPackagePath = "golang.org/x/net";
       goPackageAliases = [
         "github.com/hashicorp/go.net"
  
positive.code: 
    teleport = buildFromGitHub {
      version = 2;
      rev = "v2.0.3";
      owner = "gravitational";
      repo = "teleport";
      sha256 = "0mbyipaml4kqhharyvsm2dnf91r7yfmfqswh92zh0c62h80qssd9";
      buildInputs = [
        aws-sdk-go
        bolt
  
negative.code: 
    docker = buildFromGitHub {
      version = 2;
      rev = "0e9148b1e92dc6cf79dc57c71423297d5c11d0ca";
      owner = "docker";
      repo = "docker";
      sha256 = "1lqnpgqqyic6qq5ha9avlcpzbgl8v0359xym4l2fi7f5kjifpw7v";
      meta.useUnstable = true;
      date = "2017-04-21";
      propagatedBuildInputs = [
        distribution_for_docker
        errors
  