anchor.diff:  
     appengine = buildFromGitHub {
       version = 3;
  -    rev = "ad2570cd3913654e00c5f0183b39d2f998e54046";
  +    rev = "c5a90ac045b779001847fec87403f5cba090deae";
       owner = "golang";
       repo = "appengine";
  -    sha256 = "0a44pmnxadivzbml5vmbzjkq8kjzzm4cj0rk3449ij16k3nf448j";
  +    sha256 = "0wlardkhsq6c4b6phr9qa881bxz7h351ry829cc6d6hliji26bid";
       goPackagePath = "google.golang.org/appengine";
       excludedPackages = "aetest";
       propagatedBuildInputs = [
  
positive.code: 
    tools = buildFromGitHub {
      version = 3;
      rev = "3da34b1b520a543128e8441cd2ffffc383111d03";
      date = "2017-07-17";
      owner = "golang";
      repo = "tools";
      sha256 = "18qk09bdj26pd4iym8avpicg2kz1ldnr79xc0fljvay17sxkr63n";
      goPackagePath = "golang.org/x/tools";
  
      preConfigure = ''
  
negative.code: 
    net = buildFromGitHub {
      version = 3;
      rev = "f5079bd7f6f74e23c4d65efa0f4ce14cbd6a3c0f";
      date = "2017-07-26";
      owner = "golang";
      repo = "net";
      sha256 = "0z8w0ycj67naxwxfnzwd5srpa7h7f41imvv2vigvd9cr8s6i2iq9";
      goPackagePath = "golang.org/x/net";
      goPackageAliases = [
        "github.com/hashicorp/go.net"
  