Maybe fix hyprland.

settings/hyprland.nix

@@ -1,12 +1,38 @@
 # settings/hyprland.nix
 { config, pkgs, lib, inputs, ... }:
+let
+  hyprland-pkgs = inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system};
+  hyprutils = hyprland-pkgs.hyprutils;
+
+  # hyprutils-0.13.1 was compiled with GCC 15 (requires GLIBCXX_3.4.34) but
+  # its RPATH was patched to gcc-14.3.0-lib which only goes to GLIBCXX_3.4.33.
+  # Locate gcc-15's libstdc++ from hyprutils's own runtime closure so the
+  # version is always in sync with whatever hyprland shipped.
+  gcc15-lib = lib.head (lib.filter
+    (p: lib.hasInfix "gcc-15" p && lib.hasSuffix "-lib" p)
+    (lib.splitString "\n"
+      (lib.removeSuffix "\n"
+        (builtins.readFile (pkgs.writeReferencesToFile hyprutils)))));
+
+  hyprland-wrapped = pkgs.symlinkJoin {
+    name = hyprland-pkgs.hyprland.name;
+    paths = [ hyprland-pkgs.hyprland ];
+    nativeBuildInputs = [ pkgs.makeWrapper ];
+    postBuild = ''
+      wrapProgram $out/bin/start-hyprland \
+        --set LD_PRELOAD "${gcc15-lib}/lib/libstdc++.so.6"
+      wrapProgram $out/bin/Hyprland \
+        --set LD_PRELOAD "${gcc15-lib}/lib/libstdc++.so.6"
+    '';
+  };
+in
 {
   config = lib.mkIf (config.networking.hostName == "FredOS-Gaming") {
     programs.hyprland = {
       enable = true;
       xwayland.enable = true;
-      package      = inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system}.hyprland;
+      package      = hyprland-wrapped;
-      portalPackage = inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system}.xdg-desktop-portal-hyprland;
+      portalPackage = hyprland-pkgs.xdg-desktop-portal-hyprland;
     };
 
     xdg.portal = {
@@ -58,7 +84,7 @@
       wayland.windowManager.hyprland = {
         enable = true;
         systemd.variables = [ "--all" ];
-        package = inputs.hyprland.packages.${pkgs.stdenv.hostPlatform.system}.hyprland;
+        package = hyprland-wrapped;
 
         settings = {
           monitor = "DP-2,3440x1440@180,0x0,1";