nixos/systemd: make systemd.managerEnvironment affect systemd.settings.Manager

nixos/modules/system/boot/systemd.nix

@@ -386,6 +386,26 @@ in
       '';
     };
 
+    managerEnvironment = mkOption {
+      type =
+        with types;
+        attrsOf (
+          nullOr (oneOf [
+            str
+            path
+            package
+          ])
+        );
+      default = { };
+      example = {
+        SYSTEMD_LOG_LEVEL = "debug";
+      };
+      description = ''
+        Environment variables of PID 1. These variables are
+        *not* passed to started units.
+      '';
+    };
+
     enableCgroupAccounting = mkOption {
       default = true;
       type = types.bool;
@@ -404,29 +424,6 @@ in
       '';
       type = lib.types.submodule {
         freeformType = types.attrsOf unitOption;
-        options = {
-          ManagerEnvironment = mkOption {
-            type =
-              with types;
-              attrsOf (
-                nullOr (oneOf [
-                  str
-                  path
-                  package
-                ])
-              );
-            default = { };
-            example = {
-              SYSTEMD_LOG_LEVEL = "debug";
-            };
-            description = ''
-              Environment variables of PID 1. These variables are
-              *not* passed to started units.
-            '';
-            apply =
-              env: lib.concatStringsSep " " (lib.mapAttrsToList (n: v: "${n}=${lib.escapeShellArg v}") env);
-          };
-        };
       };
       example = {
         WatchdogDevice = "/dev/watchdog";
@@ -745,7 +742,7 @@ in
       // listToAttrs (map (withName automountToUnit) cfg.automounts);
 
     # Environment of PID 1
-    systemd.settings.Manager.ManagerEnvironment = {
+    systemd.managerEnvironment = {
       # Doesn't contain systemd itself - everything works so it seems to use the compiled-in value for its tools
       # util-linux is needed for the main fsck utility wrapping the fs-specific ones
       PATH = lib.makeBinPath (
@@ -761,6 +758,9 @@ in
         config.boot.extraSystemdUnitPaths != [ ]
       ) "${builtins.concatStringsSep ":" config.boot.extraSystemdUnitPaths}:";
     };
+    systemd.settings.Manager.ManagerEnvironment = lib.concatStringsSep " " (
+      lib.mapAttrsToList (n: v: "${n}=${lib.escapeShellArg v}") cfg.managerEnvironment
+    );
 
     system.requiredKernelConfig = map config.lib.kernelConfig.isEnabled [
       "DEVTMPFS"
@@ -871,9 +871,5 @@ in
       NixOS does not officially support this configuration and might cause your system to be unbootable in future versions. You are on your own.
     '')
     (mkRemovedOptionModule [ "systemd" "extraConfig" ] "Use systemd.settings.Manager instead.")
-    (lib.mkRenamedOptionModule
-      [ "systemd" "managerEnvironment" ]
-      [ "systemd" "settings.Manager" "ManagerEnvironment" ]
-    )
   ];
 }