nixos/mastodon: fixup sidekiq jobClasses assertion

See https://github.com/NixOS/nixpkgs/pull/225005#issuecomment-1516677321

1 files changed, 6 insertions, 5 deletions

diff --git a/nixos/modules/services/web-apps/mastodon.nix b/nixos/modules/services/web-apps/mastodon.nix
index cf5329be489c1..247eb707b15c6 100644
--- a/nixos/modules/services/web-apps/mastodon.nix
+++ b/nixos/modules/services/web-apps/mastodon.nix
@@ -588,11 +588,12 @@ in {
         '';
       }
       {
-        assertion = 1 == builtins.length
-          (lib.mapAttrsToList
-            (_: v: builtins.elem "scheduler" v.jobClasses || v.jobClasses == [ ])
-            cfg.sidekiqProcesses);
-        message = "There must be one and only one Sidekiq queue in services.mastodon.sidekiqProcesses with jobClass \"scheduler\".";
+        assertion = 1 ==
+          (lib.count (x: x)
+            (lib.mapAttrsToList
+              (_: v: builtins.elem "scheduler" v.jobClasses || v.jobClasses == [ ])
+              cfg.sidekiqProcesses));
+        message = "There must be exactly one Sidekiq queue in services.mastodon.sidekiqProcesses with jobClass \"scheduler\".";
       }
     ];