fix fallout from merge of master

pkgs/development/tools/build-managers/cmake/default.nix

@@ -1,10 +1,13 @@
 { stdenv, fetchurl
 , bzip2, curl, expat, jsoncpp, libarchive, xz, zlib
 , useNcurses ? false, ncurses, useQt4 ? false, qt4
+, wantPS ? false, ps ? null
 }:
 
 with stdenv.lib;
 
+assert wantPS -> (ps != null);
+
 let
   os = stdenv.lib.optionalString;
   majorVersion = "3.2";
@@ -41,6 +44,8 @@ stdenv.mkDerivation rec {
     ++ optional useNcurses ncurses
     ++ optional useQt4 qt4;
 
+  propagatedBuildInputs = optional wantPS ps;
+
   CMAKE_PREFIX_PATH = stdenv.lib.concatStringsSep ":" buildInputs;
 
   configureFlags =