From ce5d29c0b708cfa69eeb63c625e419c54f2f7281 Mon Sep 17 00:00:00 2001
From: Artemis Tosini <artemis.tosini@obsidian.systems>
Date: Mon, 22 Jun 2026 14:40:33 -0400
Subject: [PATCH] fontconfig: Fix cross building

The fontconfig autotools build attempts to check for va_copy with a
test program. This doesn't work cross, but we can hardcode the result.

It may be best to use meson in the future.
---
 pkgs/development/libraries/fontconfig/default.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/libraries/fontconfig/default.nix b/pkgs/development/libraries/fontconfig/default.nix
index 9e4c1fb36057..515e31901db1 100644
--- a/pkgs/development/libraries/fontconfig/default.nix
+++ b/pkgs/development/libraries/fontconfig/default.nix
@@ -67,11 +67,12 @@ stdenv.mkDerivation (finalAttrs: {
   ]
   ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
     "--with-arch=${stdenv.hostPlatform.parsed.cpu.name}"
+    "ac_cv_va_copy=C99"
   ];
 
   enableParallelBuilding = true;
 
-  doCheck = true;
+  doCheck = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
 
   installFlags = [
     # Don't try to write to /var/cache/fontconfig at install time.