anchor.diff:  
   buildGoPackage rec {
     name = "ipfs-${version}";
  -  version = "0.4.18";
  +  version = "0.4.19";
     rev = "v${version}";
   
     goPackagePath = "github.com/ipfs/go-ipfs";
  
positive.code:   extraSrcPaths = [
      (fetchgx {
        inherit name src;
        sha256 = "05d5m6c2i2kl4rvb0hddyqbidn76ljr2zryi8v2r9i8dbi0164gm";
      })
    ];
  
  
negative.code:     owner = "ipfs";
      repo = "go-ipfs";
      inherit rev;
      sha256 = "061mgkawimhw3gq506h8m6kw50a2v26qysa5kc5jdqgaqx5yvqh4";
    };
  
    meta = with stdenv.lib; {
  