anchor.diff:  
     hcl = buildFromGitHub {
       version = 2;
  -    date = "2017-01-30";
  -    rev = "88e9565e9965f4054f86c72ff1ad1bb50e560d6f";
  +    date = "2017-02-01";
  +    rev = "372e8ddaa16fd67e371e9323807d056b799360af";
       owner  = "hashicorp";
       repo   = "hcl";
  -    sha256 = "0wwz6ifvb567gg1vigfb0dlv95k18r4jihcl3m1xi3faj6rqhk64";
  +    sha256 = "08hvjpyd1yqkxj9ds4pblwnnl8illlhadqf9nfr46fyas6pavrsx";
     };
   
     hdrhistogram = buildFromGitHub {
  
positive.code: 
    net = buildFromGitHub {
      version = 2;
      rev = "f2499483f923065a842d38eb4c7f1927e6fc6e6d";
      date = "2017-01-14";
      owner  = "golang";
      repo   = "net";
      sha256 = "00220xp5nczzyhm5b71hnx8qj7xc6hxvv7h0psb1bi4sbwbgkzp3";
      goPackagePath = "golang.org/x/net";
      goPackageAliases = [
        "github.com/hashicorp/go.net"
  
negative.code:     version = 2;
      owner = "pkg";
      repo = "sftp";
      rev = "bf1c2bb0012cdea62d6c5ae7212a1bb04cfa4d89";
      date = "2017-01-31";
      sha256 = "0ls6vylv56pxbill1raf61js0i1p787mrdnmm271sqkbix53irq9";
      propagatedBuildInputs = [
        crypto
        errors
  