anchor.diff:  
     src = fetchurl {
       url = "https://notmuchmail.org/releases/${name}.tar.gz";
  -    sha256 = "0xh8vq2sa7r07xb3n13drc6gdiqhcgl0pj0za5xj43qkiwpikls0";
  +    sha256 = "0dqarmjc8544m2w7bqrqmvsfy55fw82707z3lz9cql8nr777bjmc";
     };
   
     nativeBuildInputs = [ pkgconfig ];
  
positive.code:     doxygen perl  # (optional) api docs
      pythonPackages.sphinx pythonPackages.python  # (optional) documentation -> doc/INSTALL
      bash-completion  # (optional) dependency to install bash completion
      emacs  # (optional) to byte compile emacs code
      ruby  # (optional) ruby bindings
      which dtach openssl bash  # test dependencies
    ]
  
negative.code: with stdenv.lib;
  
  stdenv.mkDerivation rec {
    version = "0.28";
    name = "notmuch-${version}";
  
    passthru = {
  