vr works again!!!

hosts/nixarawrui/default.nix

@@ -308,7 +308,18 @@
 
     alvr = {
       enable = true;
-      package = upkgs.alvr;
+
+      package = (upkgs.alvr.override {ffmpeg = upkgs.ffmpeg_7;}).overrideAttrs (old: rec {
+        postPatch =
+          (old.postPatch or "")
+          + ''
+            substituteInPlace alvr/server_openvr/src/lib.rs \
+              --replace-fail \
+              "let early_hmd_initialization = !dashboard_process_paths.is_empty();" \
+              "let early_hmd_initialization = true;"
+          '';
+      });
+
       openFirewall = true;
     };