* Set preferLocalBuild on a few trivial top-level derivations. These

tend to cause a lot of unnecessary I/O to the build machines.

svn path=/nixos/trunk/; revision=33936

modules/system/activation/top-level.nix

@@ -147,6 +147,7 @@ let
   # and makes it bootable.
   system = pkgs.stdenv.mkDerivation {
     name = "nixos-${config.system.nixosVersion}";
+    preferLocalBuild = true;
     buildCommand = systemBuilder;
     inherit children;
     kernelParams =

modules/system/upstart/upstart.nix

@@ -135,7 +135,7 @@ let
 
     in
       pkgs.runCommand ("upstart-" + job.name + ".conf")
-        { inherit (job) buildHook; inherit jobText; }
+        { inherit (job) buildHook; inherit jobText; preferLocalBuild = true; }
         ''
           eval "$buildHook"
           echo "$jobText" > $out

modules/virtualisation/qemu-vm.nix

@@ -184,6 +184,7 @@ let
     { exportReferencesGraph =
         map (x: [("closure-" + baseNameOf x) x]) config.virtualisation.pathsInNixDB;
       buildInputs = [ pkgs.perl ];
+      preferLocalBuild = true;
     }
     ''
       printRegistration=1 perl ${pkgs.pathsFromGraph} closure-* > $out
@@ -353,7 +354,7 @@ in
   # Don't run ntpd in the guest.  It should get the correct time from KVM.
   services.ntp.enable = false;
 
-  system.build.vm = pkgs.runCommand "nixos-vm" {}
+  system.build.vm = pkgs.runCommand "nixos-vm" { preferLocalBuild = true; }
     ''
       ensureDir $out/bin
       ln -s ${config.system.build.toplevel} $out/system