From 2f7435b5caa75da83305d470fdcbcfbb71a8c47c Mon Sep 17 00:00:00 2001
From: phaer <hello@phaer.org>
Date: Wed, 9 Apr 2025 15:48:41 +0200
Subject: [PATCH] virtualisation/hyperv-image: 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 hyperv --flake .#my-host`
---
 nixos/modules/virtualisation/hyperv-image.nix | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/nixos/modules/virtualisation/hyperv-image.nix b/nixos/modules/virtualisation/hyperv-image.nix
index 8f77d384a9ba..f292a60d71cd 100644
--- a/nixos/modules/virtualisation/hyperv-image.nix
+++ b/nixos/modules/virtualisation/hyperv-image.nix
@@ -73,15 +73,17 @@ in
       inherit config lib pkgs;
     };
 
-    fileSystems."/" = {
-      device = "/dev/disk/by-label/nixos";
-      autoResize = true;
-      fsType = "ext4";
-    };
+    fileSystems = lib.mkImageMediaOverride {
+      "/" = {
+        device = "/dev/disk/by-label/nixos";
+        autoResize = true;
+        fsType = "ext4";
+      };
 
-    fileSystems."/boot" = {
-      device = "/dev/disk/by-label/ESP";
-      fsType = "vfat";
+      "/boot" = {
+        device = "/dev/disk/by-label/ESP";
+        fsType = "vfat";
+      };
     };
 
     boot.growPartition = true;