anchor.diff:  
     ipfs = buildFromGitHub {
       version = 2;
  -    date = "2016-09-19";
  -    rev = "e10453b67bb8e683082ebde345d0080f05aeca12";
  +    date = "2016-09-20";
  +    rev = "300187ac52325453a632313fc8bf3423c078882e";
       owner = "ipfs";
       repo = "go-ipfs";
  -    sha256 = "38f48703cf43eda32c4071ea29546d0e746064b41ab08f1037bae867cf46edc7";
  -    gxSha256 = "04ak7xgchnrxcyw1cih2xvix73j13f0zrh425l1cv2sycjdn0n9q";
  +    sha256 = "001n6fxxdnwp6lc0lqqnmmiinc2i3cv2szv62c6gvgvv73bssnj1";
  +    gxSha256 = "03h00jk4zwgxqiq5y96w93z1ls2sickmraklz7bq0ffs3aqp5j3a";
       subPackages = [
         "cmd/ipfs"
         "cmd/ipfswatch"
  
positive.code: 
    btree = buildFromGitHub {
      version = 2;
      rev = "7b8aed74a691c0b46d439180d8cf3c9835f187cc";
      owner  = "google";
      repo   = "btree";
      sha256 = "1hz5r5xw9d3dmmaiawkdj6xf2b6wrhg5j4wbdaq3yxjzgd0k0z5c";
      date = "2016-09-21";
    };
  
    bufio_v1 = buildFromGitHub {
  
negative.code: 
    text = buildFromGitHub {
      version = 2;
      rev = "a7c023693a94aedd6b6df43ae7526bfe9d2b7d22";
      date = "2016-09-22";
      owner = "golang";
      repo = "text";
      sha256 = "002r51abslnm7d4mgvgq9nxgrm7mbh009mk8l1abgj11safzxf2v";
      goPackagePath = "golang.org/x/text";
      goPackageAliases = [ "github.com/golang/text" ];
      excludedPackages = "cmd";
    };
  
    tools = buildFromGitHub {
  