From eb1360bd663b1c9d2cbf7f2a124c8c2c359e49ce Mon Sep 17 00:00:00 2001
From: Ludovic Courtès <ludo@gnu.org>
Date: Tue, 17 Jan 2012 16:34:10 +0000
Subject: hwloc: Make it easy to disable optional dependencies; fix
 cross-builds.

svn path=/nixpkgs/trunk/; revision=31606
---
 pkgs/development/libraries/hwloc/default.nix | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'pkgs/development/libraries/hwloc/default.nix')

diff --git a/pkgs/development/libraries/hwloc/default.nix b/pkgs/development/libraries/hwloc/default.nix
index 303f2750d82a..09de2e702e13 100644
--- a/pkgs/development/libraries/hwloc/default.nix
+++ b/pkgs/development/libraries/hwloc/default.nix
@@ -9,7 +9,12 @@ stdenv.mkDerivation rec {
   };
 
   # XXX: libX11 is not directly needed, but needed as a propagated dep of Cairo.
-  buildInputs = [ pkgconfig cairo expat ncurses libX11 ];
+  buildNativeInputs = [ pkgconfig ];
+
+  # Filter out `null' inputs.  This allows users to `.override' the
+  # derivation and set optional dependencies to `null'.
+  buildInputs = stdenv.lib.filter (x: x != null)
+   [ cairo expat ncurses libX11 ];
 
   doCheck = true;
 
-- 
cgit 1.4.1