Fixed issues with Steam not wanting to launch Gamescope. Tips from: NixOS/nixpkgs#162562 (comment)

Author: haysidney

configuration.nix

@@ -549,7 +549,32 @@
   };
 
   programs = {
-    steam.enable = true;
+    steam = {
+      enable = true;
+      package = pkgs.steam.override {
+        extraEnv = {};
+        extraLibraries = pkgs: with pkgs; [
+          xorg.libXcursor
+          xorg.libXi
+          xorg.libXinerama
+          xorg.libXScrnSaver
+          libpng
+          libpulseaudio
+          libvorbis
+          stdenv.cc.cc.lib
+          libkrb5
+          keyutils
+        ];
+      };
+      gamescopeSession = {
+        enable = true;
+        args = [
+          "--rt"
+          "-f"
+          "-o 10"
+        ];
+      };
+    };
     git.enable = true;
     bash = {
       promptInit = ''