lib/call-machine: Introduce .build shortcut

The shortcut is mainly to make things a bit easier, instead of:

nix-build '<vuizvui/machines>' \
  -A aszlig.tishtushi.eval.config.system.build.toplevel

We can now do something like this:

nix-build '<vuizvui/machines>' \
  -A aszlig.tishtushi.build

... in order to get a system store path out of a machine definition.

This also fixes an evaluation error in the top-level default.nix. Thanks
to @Profpatsch for bringing this to my attention.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/default.nix b/default.nix
index f2ea79e2..a6ac9441 100644
--- a/default.nix
+++ b/default.nix
@@ -3,9 +3,10 @@
 with (import (import ./nixpkgs-path.nix) { inherit system; }).lib;
 
 {
-  machines = mapAttrsRecursiveCond (m: !(m ? build)) (path: attrs:
-    attrs.build.config.system.build.toplevel
-  ) (import ./machines { inherit system; });
+  machines = let
+    getBuild = const (getAttr "build");
+    allMachines = import ./machines { inherit system; };
+  in mapAttrsRecursiveCond (m: !(m ? eval)) getBuild allMachines;
 
   pkgs = import ./pkgs {
     pkgs = import (import ./nixpkgs-path.nix) args;