anchor.diff:  
       outputHashMode = "recursive";
       outputHashAlgo = "sha256";
  -    outputHash = "1v3h0c7kfifb6wsfxyv5j1wc7rlxbb7r0pgd4s340wiyxnllzzhk";
  +    outputHash = "1bk3yd10cq6vlgmh2qawl82m29yi5zcbsdlz17xyy76sg2ka622a";
     };
   
     configureFlags =
  
positive.code:   ctlpath = lib.makeBinPath [ bash gnused gnugrep coreutils utillinux procps ];
  
  in stdenv.mkDerivation rec {
    version = "18.01";
    name = "ejabberd-${version}";
  
    src = fetchurl {
      url = "https://www.process-one.net/downloads/ejabberd/${version}/${name}.tgz";
      sha256 = "01i2n8mlgw293jdf4172f9q8ca8m35vysjws791p7nynpfdb4cn6";
    };
  
    nativeBuildInputs = [ fakegit ];
  
    buildInputs = [ erlang openssl expat libyaml gd ]
      ++ lib.optional withSqlite sqlite
      ++ lib.optional withPam pam
      ++ lib.optional withZlib zlib
  
negative.code: { stdenv, writeScriptBin, makeWrapper, lib, fetchurl, git, cacert, libpng, libjpeg, libwebp
  , erlang, openssl, expat, libyaml, bash, gnused, gnugrep, coreutils, utillinux, procps, gd
  , flock
  , withMysql ? false
  