From 61ba0446582326e339c2dfbf2b96cc37b16db6f2 Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Wed, 9 Apr 2025 12:52:50 +0200
Subject: [PATCH] virtualisation/oci-common: use mkImageMediaOverride...

...for filesystem options. Before this change,
users would typically encounter conflicting option definitions
when trying to build an image for a generic nixos closure, i.e.
`nixos-rebuild build-image --image-variant common --flake .#my-host`
---
 nixos/modules/virtualisation/oci-common.nix | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/nixos/modules/virtualisation/oci-common.nix b/nixos/modules/virtualisation/oci-common.nix
index d92cda7de437..73b68c57f3e2 100644
--- a/nixos/modules/virtualisation/oci-common.nix
+++ b/nixos/modules/virtualisation/oci-common.nix
@@ -30,15 +30,17 @@ in
 
   boot.growPartition = true;
 
-  fileSystems."/" = {
-    device = "/dev/disk/by-label/nixos";
-    fsType = "ext4";
-    autoResize = true;
-  };
+  fileSystems = lib.mkImageMediaOverride {
+    "/" = {
+      device = "/dev/disk/by-label/nixos";
+      fsType = "ext4";
+      autoResize = true;
+    };
 
-  fileSystems."/boot" = lib.mkIf cfg.efi {
-    device = "/dev/disk/by-label/ESP";
-    fsType = "vfat";
+    "/boot" = lib.mkIf cfg.efi {
+      device = "/dev/disk/by-label/ESP";
+      fsType = "vfat";
+    };
   };
 
   boot.loader.efi.canTouchEfiVariables = false;