From fe58c181d3573e35da55bf43c3827d2e7627c8af Mon Sep 17 00:00:00 2001
From: Maximilian Bosch <maximilian@mbosch.me>
Date: Sun, 31 Oct 2021 14:33:13 +0100
Subject: [PATCH] libspf2: fix build w/glibc-2.34

Failing Hydra build: https://hydra.nixos.org/build/156229214
---
 pkgs/development/libraries/libspf2/default.nix | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/libspf2/default.nix b/pkgs/development/libraries/libspf2/default.nix
index c48c71e14485..203f2768e37b 100644
--- a/pkgs/development/libraries/libspf2/default.nix
+++ b/pkgs/development/libraries/libspf2/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, autoreconfHook }:
+{ lib, stdenv, fetchFromGitHub, autoreconfHook, fetchpatch }:
 
 with lib;
 
@@ -13,6 +13,14 @@ stdenv.mkDerivation rec {
     sha256 = "03iiaafdcwh220pqignk407h6klrakwz0zkb8iwk6nkwipkwvhsx";
   };
 
+  patches = [
+    # glibc-2.34 compat
+    (fetchpatch {
+      url = "https://raw.githubusercontent.com/gentoo/gentoo/dbb8a5c9f749cc11e61cfe558f164b165cbc30cb/mail-filter/libspf2/files/libspf2-1.2.11-undefined-dn_.patch";
+      sha256 = "sha256-6JVVkVGCcFJsNeBdVTPcLhW4KoHLY4ai/KXDMliXgPA=";
+    })
+  ];
+
   postPatch = ''
     # disable static bins compilation
     sed -i \