gnutar: patch to build on darwin

pkgs/tools/archivers/gnutar/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl }:
+{ stdenv, fetchurl, autoreconfHook }:
 
 stdenv.mkDerivation rec {
   name = "gnutar-${version}";
@@ -9,6 +9,9 @@ stdenv.mkDerivation rec {
     sha256 = "0qkm2k9w8z91hwj8rffpjj9v1vhpiriwz4cdj36k9vrgc3hbzr30";
   };
 
+  patches = stdenv.lib.optional stdenv.isDarwin ./gnutar-1.28-darwin.patch;
+  buildInputs = stdenv.lib.optional stdenv.isDarwin autoreconfHook;
+
   # May have some issues with root compilation because the bootstrap tool
   # cannot be used as a login shell for now.
   FORCE_UNSAFE_CONFIGURE = stdenv.lib.optionalString (stdenv.system == "armv7l-linux" || stdenv.isSunOS) "1";