pass builderArgs to config and extract builds

flake.nix

@@ -57,6 +57,7 @@
           externalModules = [
             ci-agent.nixosModules.agent-profile
             home.nixosModules.home-manager
+            ./modules/customBuilds.nix
           ];
         };
         hosts = nixos.lib.mkMerge [

lib/devos/mkHomeConfigurations.nix

@@ -4,9 +4,10 @@ nixosConfigurations:
 
 with lib;
 let
-  mkHomes = host: config:
-    mapAttrs' (user: v: nameValuePair "${user}@${host}" v.home)
-      config.config.system.build.homes;
+  mkHomes = hostName: host:
+    mapAttrs' (user: v: nameValuePair "${user}@${hostName}" v.home)
+      # So this function is useful for non-devos hosts
+      (host.config.system.build.homes or host.config.home-manager.users);
 
   hmConfigs = mapAttrs mkHomes nixosConfigurations;
 

lib/mkFlake/default.nix

@@ -64,7 +64,10 @@ lib.systemFlake (lib.mergeAny
     hostDefaults = lib.mergeAny hostDefaults {
       specialArgs.suites = cfg.nixos.suites;
       modules = cfg.nixos.hostDefaults.externalModules ++ defaultModules;
-      builder = os.devosSystem { inherit self inputs; };
+      builder = args: args.specialArgs.channel.input.lib.nixosSystem (lib.mergeAny args {
+        # So modules and functions can create their own version of the build
+        modules = [ { lib.builderArgs = args; } ];
+      });
     };
 
     nixosModules = lib.exporter.modulesFromList cfg.nixos.hostDefaults.modules;

lib/modules.nix

@@ -43,6 +43,7 @@
 
       _module.args = {
         inherit self;
+        devlib = lib;
         hosts = builtins.mapAttrs (_: host: host.config)
           (removeAttrs self.nixosConfigurations [ config.networking.hostName ]);
       };
@@ -111,18 +112,5 @@
       };
     };
 
-  hmConfig =
-    { config, ... }: {
-      home-manager.useUserPackages = lib.mkForce false;
-      home-manager.sharedModules = [
-        {
-          home.sessionVariables = {
-            inherit (config.environment.sessionVariables) NIX_PATH;
-          };
-          xdg.configFile."nix/registry.json".text =
-            config.environment.etc."nix/registry.json".text;
-        }
-      ];
-    };
 }
 

lib/pkgs-lib/tests/default.nix

@@ -23,11 +23,9 @@ let
       nixosTesting =
         (import "${toString pkgs.path}/nixos/lib/testing-python.nix" {
           inherit (pkgs) system;
-          inherit (host.config.lib) specialArgs;
+          inherit (host.config.lib.builderArgs) specialArgs;
           inherit pkgs;
-          extraConfigurations = [
-            host.config.lib.testModule
-          ];
+          extraConfigurations = host._module.args.modules;
         });
     in
     test:

modules/customBuilds.nix

@@ -0,0 +1,29 @@
+{ lib, self, devlib, config, modules, channel, ... }:
+let
+  mkBuild = buildModule:
+    channel.input.lib.nixosSystem (devlib.mergeAny config.lib.builderArgs {
+      modules = [ buildModule ];
+    });
+in
+{
+  system.build = {
+    iso = (mkBuild (devlib.modules.isoConfig {
+      inherit self;
+      inherit (self) inputs;
+      fullHostConfig = config;
+    })).config.system.build.isoImage;
+
+    homes = (mkBuild ({ config, ... }: {
+      home-manager.useUserPackages = lib.mkForce false;
+      home-manager.sharedModules = [
+        {
+          home.sessionVariables = {
+            inherit (config.environment.sessionVariables) NIX_PATH;
+          };
+          xdg.configFile."nix/registry.json".text =
+            config.environment.etc."nix/registry.json".text;
+        }
+      ];
+    })).config.home-manager.users;
+  };
+}