anchor.diff:  
     google-cloud-go-compute-metadata = buildFromGitHub {
       inherit (google-cloud-go) rev date owner repo sha256 version goPackagePath goPackageAliases meta;
  -    subPackages = [ "compute/metadata" "internal" ];
  -    buildInputs = [ net ];
  +    subPackages = [
  +      "compute/metadata"
  +      "internal"
  +    ];
  +    buildInputs = [
  +      #gax-go
  +      net
  +    ];
     };
   
     gopcap = buildFromGitHub {
  
positive.code: 
    net = buildFromGitHub {
      version = 2;
      rev = "0e2717dc3cc05907dc23096ef3a9086ea93f567f";
      date = "2016-11-10";
      owner  = "golang";
      repo   = "net";
      sha256 = "0fxx3cfdakhcv1f0zs6h9yikakdvziwzaj6a64hk2fcj5yk8lpn7";
      goPackagePath = "golang.org/x/net";
      goPackageAliases = [
        "github.com/hashicorp/go.net"
  
negative.code: 
    google-cloud-go = buildFromGitHub {
      version = 2;
      date = "2016-11-15";
      rev = "30b36efdf5c81a1d3f9fac38e1496c29e8adc420";
      owner = "GoogleCloudPlatform";
      repo = "google-cloud-go";
      sha256 = "e7d33facde617abac9a8cb4500bfbd1492a241e0ac22d36337e0c6891ac37ba6";
      goPackagePath = "cloud.google.com/go";
      goPackageAliases = [
        "google.golang.org/cloud"
  