anchor.diff:      };
       buildInputs = [ pkgs.zookeeper_mt ];
       # fix "error: format not a string literal and no format arguments [-Werror=format-security]"
  -    hardeningDisable = stdenv.lib.optional (stdenv.lib.versionAtLeast perl.version "5.28") "format";
  +    hardeningDisable = [ "format" ];
       NIX_CFLAGS_COMPILE = "-I${pkgs.zookeeper_mt}/include";
       NIX_CFLAGS_LINK = "-L${pkgs.zookeeper_mt.out}/lib -lzookeeper_mt";
       meta = {
  
positive.code:     buildInputs = [ Filepushd ];
    };
  
    ModuleCoreList = null; # part of Perl 5.28
  
    ModuleExtractUse = buildPerlModule rec {
       name = "Module-ExtractUse-0.343";
       src = fetchurl {
  
negative.code:   threads = null; # part of Perl 5.28
    TimeHiRes = null; # part of Perl 5.28
    UnicodeCollate = null; # part of Perl 5.28
    ModuleCoreList = null; # part of Perl 5.28.2
  
    ArchiveZip_1_53 = self.ArchiveZip;
    Autobox = self.autobox;
  