From e1a734cee22049a911dae7f0cf54371b68745d5e Mon Sep 17 00:00:00 2001
From: Nikolay Amiantov <ab@fmap.me>
Date: Wed, 27 Jan 2016 10:29:38 +0300
Subject: [PATCH] libva: fix likely problem on Darwin

---
 pkgs/development/libraries/libva/default.nix | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/pkgs/development/libraries/libva/default.nix b/pkgs/development/libraries/libva/default.nix
index 42ce11c7b4d..e8de6ac284e 100644
--- a/pkgs/development/libraries/libva/default.nix
+++ b/pkgs/development/libraries/libva/default.nix
@@ -1,8 +1,10 @@
-{ stdenv, fetchurl, libX11, pkgconfig, libXext, libdrm, libXfixes, wayland, libffi
+{ stdenv, lib, fetchurl, libX11, pkgconfig, libXext, libdrm, libXfixes, wayland, libffi
 , mesa_noglu ? null
 }:
 
-stdenv.mkDerivation rec {
+let
+  withMesa = mesa_noglu != null;
+in stdenv.mkDerivation rec {
   name = "libva-1.6.2";
 
   src = fetchurl {
@@ -12,14 +14,14 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ libX11 libXext pkgconfig libdrm libXfixes wayland libffi mesa_noglu ];
 
-  configureFlags = stdenv.lib.optionals (mesa_noglu != null) [
+  configureFlags = lib.optionals withMesa [
     "--with-drivers-path=${mesa_noglu.driverLink}/lib/dri"
     "--enable-glx"
   ];
 
-  installFlags = [ "DESTDIR=$(out)" ];
+  installFlags = lib.optional withMesa "DESTDIR=$(out)";
 
-  postInstall = ''
+  postInstall = lib.optionalString withMesa ''
     cp -r $out/${mesa_noglu.driverLink}/* $out
     cp -r $out/$out/* $out
     rm -rf $out/run $out/$(echo "$out" | cut -d "/" -f2)