Enable grub zfsSupport if zfs is built into the initrd

nixos/modules/system/boot/loader/grub/grub.nix

@@ -7,7 +7,7 @@ let
   cfg = config.boot.loader.grub;
 
   realGrub = if cfg.version == 1 then pkgs.grub
-    else pkgs.grub2.override { zfsSupport = cfg.zfsSupport };
+    else pkgs.grub2.override { zfsSupport = cfg.zfsSupport; };
 
   grub =
     # Don't include GRUB if we're only generating a GRUB menu (e.g.,

nixos/modules/tasks/filesystems/zfs.nix

@@ -148,6 +148,10 @@ in
           '';
       };
 
+      boot.loader.grub = mkIf inInitrd {
+        zfsSupport = true;
+      };
+
       systemd.services."zpool-import" = {
         description = "Import zpools";
         after = [ "systemd-udev-settle.service" ];