anchor.diff:      postConfigure = ''
         mv "$TMPDIR/Godeps" "go/src/$goPackagePath"
       '';
  +    meta.useUnstable = true;
     };
   
     json-filter = buildFromGitHub {
  
positive.code: 
    crypto = buildFromGitHub {
      version = 2;
      rev = "6ab629be5e31660579425a738ba8870beb5b7404";
      date = "2016-09-19";
      owner    = "golang";
      repo     = "crypto";
      sha256 = "1fkf5fdny2d4zwrijxr7jv041hcs7rsqhmd9agmp11s9brvbx2x4";
      goPackagePath = "golang.org/x/crypto";
      goPackageAliases = [
        "code.google.com/p/go.crypto"
  
negative.code: 
    btree = buildFromGitHub {
      version = 2;
      rev = "7364763242911ab6d418d2722e237194938ebad0";
      owner  = "google";
      repo   = "btree";
      sha256 = "16cnqa77msnikx3h18nbny23csr2mbai050aa78niznv0kyzg3lp";
      date = "2016-09-23";
    };
  
    bufio_v1 = buildFromGitHub {
  