anchor.diff:        tar-utils
       ];
       meta.useUnstable = true;
  -    date = "2017-02-08";
  +    date = "2017-03-01";
     };
   
     go-ipfs-util = buildFromGitHub {
  
positive.code: 
    tools = buildFromGitHub {
      version = 2;
      rev = "718875e4f9a39b5a303f3fa67a7dd9367b07c02f";
      date = "2017-02-28";
      owner = "golang";
      repo = "tools";
      sha256 = "1sj767i7ipwnwvvmy8b5j5iv6incahbmsmq0l85q8xjj9wx2mhqg";
      goPackagePath = "golang.org/x/tools";
      goPackageAliases = [ "code.google.com/p/go.tools" ];
  
  
negative.code: 
    go-ipfs-api = buildFromGitHub {
      version = 2;
      rev = "57e8d73c27b8e64b8d025bc24afa0439ccca309a";
      owner  = "ipfs";
      repo   = "go-ipfs-api";
      sha256 = "0wwk2xywpmzcifi56bmhn6d37x4mvrf6hwb9k7xsj90mlh34an2w";
      excludedPackages = "tests";
      propagatedBuildInputs = [
        go-floodsub
  