From 3b773c7baee7221d1bbe0280d3dfc5790583ff0c Mon Sep 17 00:00:00 2001
From: Emily <vcs@emily.moe>
Date: Mon, 11 Aug 2025 15:36:06 +0100
Subject: [PATCH] swiftPackages.Dispatch: backport patch for modern LLVM

---
 .../compilers/swift/libdispatch/default.nix           | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/compilers/swift/libdispatch/default.nix b/pkgs/development/compilers/swift/libdispatch/default.nix
index 3760dfb405b9..4b30a1d80673 100644
--- a/pkgs/development/compilers/swift/libdispatch/default.nix
+++ b/pkgs/development/compilers/swift/libdispatch/default.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   callPackage,
+  fetchpatch,
   cmake,
   ninja,
   useSwift ? true,
@@ -31,7 +32,15 @@ stdenv.mkDerivation {
     swift
   ];
 
-  patches = [ ./disable-swift-overlay.patch ];
+  patches = [
+    # Fix the build with modern Clang.
+    (fetchpatch {
+      url = "https://github.com/swiftlang/swift-corelibs-libdispatch/commit/30bb8019ba79cdae0eb1dc0c967c17996dd5cc0a.patch";
+      hash = "sha256-wPZQ4wtEWk8HaKMfzjamlU6p/IW5EFiTssY63rGM+ZA=";
+    })
+
+    ./disable-swift-overlay.patch
+  ];
 
   cmakeFlags = lib.optional useSwift "-DENABLE_SWIFT=ON";