anchor.diff:  }:
   
   let
  -  date = "2019-01-14";
  -  rev = "8630059e6ac363bea39e54df3f8115da5a5c2c5d";
  +  date = "2019-01-23";
  +  rev = "35fca2f044d375b1590f499cfd34bef38ca0f8f1";
   in
   stdenv.mkDerivation {
     name = "bcachefs-tools-${date}";
  
positive.code:   src = fetchzip {
      version = 6;
      url = "https://evilpiepirate.org/git/bcachefs-tools.git/snapshot/bcachefs-tools-${rev}.tar.xz";
      multihash = "QmZ55yYDPRW9ZhH8doR5LqDWrWFJmBBYrTZKdBWNPdj5Xh";
      sha256 = "ad8f6433a18fa8525499ea4cb1a97fa008653ab3aeaf7b43022c03300f2e55a2";
    };
  
    buildInputs = [
      keyutils
      libaio
      libnih
      libscrypt
      libsodium
      liburcu
  
negative.code: 
  , keyutils
  , libaio
  , libscrypt
  , libsodium
  , liburcu
  