anchor.diff:        tar-utils
       ];
       meta.useUnstable = true;
  -    date = "2017-02-08";
  +    date = "2017-03-01";
     };
   
     go-ipfs-util = buildFromGitHub {
  
positive.code: 
    go-ethereum = buildFromGitHub {
      version = 2;
      date = "2017-02-28";
      rev = "167be7f260763bb21e703d304b553142d5422266";
      owner  = "ethereum";
      repo   = "go-ethereum";
      sha256 = "1mq33l0nf2f8jdgjs0rp4aglzfjs172q90ipgxayygk50i59rn29";
      subPackages = [
        "crypto/sha3"
      ];
  
negative.code: 
    ipfs = buildFromGitHub {
      version = 2;
      rev = "v0.4.6";
      owner = "ipfs";
      repo = "go-ipfs";
      sha256 = "1yj0i2n8ww7fplkqpnk7106lc514wjiik4wagja2gp0miq40xh8v";
      gxSha256 = "1wrx86118llzdpy1ksgn5v86ra3ickcjkf35pg3xjd3jvqy0rjqb";
      subPackages = [
        "cmd/ipfs"
        "cmd/ipfswatch"
  