From 6510ec5acdd465a016e5671ffa99460ef70e6c25 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Fri, 17 Dec 2021 14:34:30 +0100
Subject: [PATCH] nixos: Make system.build.vm a standard attribute based on
 vmVariant

---
 flake.nix                                 |  5 -----
 nixos/default.nix                         |  4 +---
 nixos/modules/virtualisation/build-vm.nix | 11 ++++++++++-
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/flake.nix b/flake.nix
index 3060ffdd649e..01d52ae38624 100644
--- a/flake.nix
+++ b/flake.nix
@@ -45,11 +45,6 @@
                   system.nixos.versionSuffix =
                     ".${final.substring 0 8 (self.lastModifiedDate or self.lastModified or "19700101")}.${self.shortRev or "dirty"}";
                   system.nixos.revision = final.mkIf (self ? rev) self.rev;
-
-                  system.build = {
-                    vm = lib.mkDefault config.virtualisation.vmVariant.system.build.vm;
-                    vmWithBootLoader = lib.mkDefault config.virtualisation.vmVariantWithBootLoader.system.build.vm;
-                  };
                 })
               ];
           });
diff --git a/nixos/default.nix b/nixos/default.nix
index 27a0fd73ecd7..6beb4cd3a7df 100644
--- a/nixos/default.nix
+++ b/nixos/default.nix
@@ -16,7 +16,5 @@ in
 
   system = eval.config.system.build.toplevel;
 
-  vm = eval.config.virtualisation.vmVariant.system.build.vm;
-
-  vmWithBootLoader = eval.config.virtualisation.vmVariantWithBootLoader.system.build.vm;
+  inherit (eval.config.system.build) vm vmWithBootLoader;
 }
diff --git a/nixos/modules/virtualisation/build-vm.nix b/nixos/modules/virtualisation/build-vm.nix
index d856b1b502b6..3baa84cce018 100644
--- a/nixos/modules/virtualisation/build-vm.nix
+++ b/nixos/modules/virtualisation/build-vm.nix
@@ -1,4 +1,4 @@
-{ extendModules, lib, ... }:
+{ config, extendModules, lib, ... }:
 let
 
   inherit (lib)
@@ -43,4 +43,13 @@ in
     };
 
   };
+
+  config = {
+
+    system.build = {
+      vm = lib.mkDefault config.virtualisation.vmVariant.system.build.vm;
+      vmWithBootLoader = lib.mkDefault config.virtualisation.vmVariantWithBootLoader.system.build.vm;
+    };
+
+  };
 }