From 10cbd003966e67ad4ae40a82ba1a8496cd239536 Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Wed, 16 Nov 2011 21:04:02 +0000
Subject: [PATCH] Allow cross-compiling configurations to explicitly give a
 system string when cross-building nix

svn path=/nixpkgs/trunk/; revision=30458
---
 pkgs/tools/package-management/nix/unstable.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pkgs/tools/package-management/nix/unstable.nix b/pkgs/tools/package-management/nix/unstable.nix
index da70ed6bb0f..921e902e061 100644
--- a/pkgs/tools/package-management/nix/unstable.nix
+++ b/pkgs/tools/package-management/nix/unstable.nix
@@ -36,7 +36,9 @@ stdenv.mkDerivation rec {
         --with-dbd-sqlite=${perlPackages.DBDSQLite}/lib/perl5/site_perl
         --disable-init-state
         CFLAGS=-O3 CXXFLAGS=-O3
-      '';
+      '' + stdenv.lib.optionalString (
+          stdenv.cross ? nix && stdenv.cross.nix ? system
+      ) ''--with-system=${stdenv.cross.nix.system}'';
     doCheck = false;
   };