anchor.diff:    # stray test failure
     doCheck = false;
   
  +  nativeBuildInputs = stdenv.lib.optionals stdenv.isDarwin [ shortenPerlShebang ];
     buildInputs = [ ArchiveZip ArchiveCpio file ];
   
     perlPostHook = ''
  
positive.code: { lib, file, fetchFromGitLab, buildPerlPackage, ArchiveZip, ArchiveCpio }:
  
  buildPerlPackage rec {
    pname = "strip-nondeterminism";
  
negative.code:     rm $out/share/man/man1/dh_strip_nondeterminism.1.gz
    '';
  
    postInstall = stdenv.lib.optionalString stdenv.isDarwin ''
      shortenPerlShebang $out/bin/strip-nondeterminism
    '';
  
    meta = with stdenv.lib; {
      description = "A Perl module for stripping bits of non-deterministic information";
      homepage = "https://reproducible-builds.org/";
      license = licenses.gpl3;
  