From 4c41c412a0c6353e6a49b484783b4c925064718c Mon Sep 17 00:00:00 2001
From: Joachim Fasting <joachifm@fastmail.fm>
Date: Sun, 23 Oct 2016 17:26:18 +0200
Subject: [PATCH] nix gc service: fix use of startAt

`startAt = ""` as in `startAt = optionalString false ...` results
in an invalid timer unit (due to "" being promoted to a singleton
list and not filtered out).

Ref: c9941c4b5ef7acc1cb8d734acb383410d99c01ba
---
 nixos/modules/services/misc/nix-gc.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/modules/services/misc/nix-gc.nix b/nixos/modules/services/misc/nix-gc.nix
index 5c13da6e83d..304168c65b0 100644
--- a/nixos/modules/services/misc/nix-gc.nix
+++ b/nixos/modules/services/misc/nix-gc.nix
@@ -53,7 +53,7 @@ in
     systemd.services.nix-gc =
       { description = "Nix Garbage Collector";
         script = "exec ${config.nix.package.out}/bin/nix-collect-garbage ${cfg.options}";
-        startAt = optionalString cfg.automatic cfg.dates;
+        startAt = optional cfg.automatic cfg.dates;
       };
 
   };