From a10f3197fc893c98a74ae3bb3610b95559951e7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sandro=20J=C3=A4ckel?= <sandro.jaeckel@gmail.com>
Date: Mon, 20 Mar 2023 01:11:23 +0100
Subject: [PATCH] systemd-lib: fix building -.slice (root slice)

The error was:

dirname: invalid option -- '.'
Try 'dirname --help' for more information.
---
 nixos/lib/systemd-lib.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/lib/systemd-lib.nix b/nixos/lib/systemd-lib.nix
index c6c8753d5325..a21450708fe5 100644
--- a/nixos/lib/systemd-lib.nix
+++ b/nixos/lib/systemd-lib.nix
@@ -24,7 +24,7 @@ in rec {
         }
         ''
           name=${shellEscape name}
-          mkdir -p "$out/$(dirname "$name")"
+          mkdir -p "$out/$(dirname -- "$name")"
           echo -n "$text" > "$out/$name"
         ''
     else