From 817b9f692dca44d728e5ad431875e6df63977840 Mon Sep 17 00:00:00 2001
From: Nick Hu <me@nickhu.co.uk>
Date: Wed, 7 May 2025 10:36:41 +0100
Subject: [PATCH] docbook_sgml_dtd: fix unreachable source

---
 pkgs/data/sgml+xml/schemas/sgml-dtd/docbook/4.1.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/data/sgml+xml/schemas/sgml-dtd/docbook/4.1.nix b/pkgs/data/sgml+xml/schemas/sgml-dtd/docbook/4.1.nix
index 4a106db44057..d20313d7e237 100644
--- a/pkgs/data/sgml+xml/schemas/sgml-dtd/docbook/4.1.nix
+++ b/pkgs/data/sgml+xml/schemas/sgml-dtd/docbook/4.1.nix
@@ -13,7 +13,7 @@ let
   };
 
   isoents = fetchurl {
-    url = "http://www.oasis-open.org/cover/ISOEnts.zip";
+    url = "https://web.archive.org/web/20250220122223/http://xml.coverpages.org/ISOEnts.zip";
     sha256 = "1clrkaqnvc1ja4lj8blr0rdlphngkcda3snm7b9jzvcn76d3br6w";
   };