From bc58993f99a817e70905acfaaa43b5dcf5b63e31 Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <slyich@gmail.com>
Date: Mon, 25 May 2026 08:56:32 +0100
Subject: [PATCH] libffi_3_3: fix `gcc-15` build

Without the chnage the build fails in `master` as
https://hydra.nixos.org/build/329329821:

```
FAIL: libffi.call/va_struct2.c -W -Wall -Wno-psabi -O0 (test for excess errors)
FAIL: libffi.call/va_struct2.c -W -Wall -Wno-psabi -O2 (test for excess errors)
FAIL: libffi.call/va_struct3.c -W -Wall -Wno-psabi -O0 (test for excess errors)
FAIL: libffi.call/va_struct3.c -W -Wall -Wno-psabi -O2 (test for excess errors)
```

ZHF: #516381
---
 pkgs/by-name/li/libffi_3_3/package.nix | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/by-name/li/libffi_3_3/package.nix b/pkgs/by-name/li/libffi_3_3/package.nix
index fbf27320c26e..791799bc3337 100644
--- a/pkgs/by-name/li/libffi_3_3/package.nix
+++ b/pkgs/by-name/li/libffi_3_3/package.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchurl,
+  fetchpatch,
 
   doCheck ? true, # test suite depends on dejagnu which cannot be used during bootstrapping
   dejagnu,
@@ -16,7 +17,15 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-cvunkicD3fp6Ao1ROsFahcjVTI1n9V+lpIAohdxlIFY=";
   };
 
-  patches = [ ];
+  patches = [
+    # Backport gcc-15 fix:
+    #   https://github.com/libffi/libffi/pull/861
+    (fetchpatch {
+      name = "gcc-15.patch";
+      url = "https://github.com/libffi/libffi/commit/0859f8431242d5adff21420b9cab538d2af527b5.patch";
+      hash = "sha256-Py4ZAhVyXsfLxr4pnYAH7/lcsQOmpToFgvjQvLg9XVc=";
+    })
+  ];
 
   outputs = [
     "out"