From bc4a29043d82cf3125aedfe9b19fb8c923583592 Mon Sep 17 00:00:00 2001
From: chn <chn@chn.moe>
Date: Mon, 17 Nov 2025 10:32:25 +0800
Subject: [PATCH] modules.system.nix: simplify march handling

---
 modules/system/nix.nix | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/modules/system/nix.nix b/modules/system/nix.nix
index ce0f7c08..88d14e2d 100644
--- a/modules/system/nix.nix
+++ b/modules/system/nix.nix
@@ -3,7 +3,11 @@ inputs:
   options.nixos.system.nix = let inherit (inputs.lib) mkOption types; in
   {
     # marches allowed to be compiled on this machine
-    marches = mkOption { type = types.nullOr (types.listOf types.nonEmptyStr); default = null; };
+    marches = mkOption
+    {
+      type = types.listOf types.nonEmptyStr;
+      default = with inputs.config.nixos.system.nixpkgs; if march == null then [] else [ march ];
+    };
     substituters = mkOption { type = types.listOf types.nonEmptyStr; default = [ "https://nix-store.chn.moe" ]; };
     remote =
     {
@@ -63,17 +67,7 @@ inputs:
       };
     }
     # marches
-    {
-      nix.settings.system-features =
-      (map
-        (march: "gccarch-${march}")
-        (
-          if nix.marches == null then
-            (with inputs.config.nixos.system.nixpkgs; if march == null then [] else [ march ])
-          else nix.marches
-        ))
-      ++ (with inputs.config.nixos.system.nixpkgs; if march == null then [] else [ "gccarch-exact-${march}" ]);
-    }
+    { nix.settings.system-features = builtins.map (march: "gccarch-${march}") nix.marches; }
     # includeBuildDependencies
     { system.includeBuildDependencies = inputs.topInputs.self.config.branch == "archive"; }
     # substituters