Add patch to fix Lutris with recent gtk3 version

configs/games.nix

@@ -2,6 +2,16 @@
 {
   hardware.opengl.driSupport32Bit = true;
   home-manager.users.froidmpa = {pkgs, config, ...}: {
+    nixpkgs.config = {
+      allowUnfree = true;
+      packageOverrides = super: let self = super.pkgs; in {
+        lutris-unwrapped = super.lutris-unwrapped.overridePythonAttrs (oldAttrs: rec {
+          patches = [
+            ./lutris_sort_new_with_model_fix.patch
+          ];
+        });
+      };
+    };
     home.packages = with pkgs; [
       steam
       lutris

configs/lutris_sort_new_with_model_fix.patch

@@ -0,0 +1,26 @@
+From 12a458db3c590c3f1972594e091a24cb4d65b610 Mon Sep 17 00:00:00 2001
+From: Mathieu Comandon <strycore@gmail.com>
+Date: Wed, 1 Jan 2020 12:47:55 -0800
+Subject: [PATCH] Support both sort_new_with_model and new_with_model
+
+---
+ lutris/gui/views/store.py | 6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+diff --git a/lutris/gui/views/store.py b/lutris/gui/views/store.py
+index 9e843e9e4..8fe5decf5 100644
+--- a/lutris/gui/views/store.py
++++ b/lutris/gui/views/store.py
+@@ -140,7 +140,11 @@ def __init__(
+         self.prevent_sort_update = False  # prevent recursion with signals
+         self.modelfilter = self.store.filter_new()
+         self.modelfilter.set_visible_func(self.filter_view)
+-        self.modelsort = Gtk.TreeModelSort.sort_new_with_model(self.modelfilter)
++        try:
++            self.modelsort = Gtk.TreeModelSort.sort_new_with_model(self.modelfilter)
++        except AttributeError:
++            # Apparently some API breaking changes on GTK minor versions.
++            self.modelsort = Gtk.TreeModelSort.new_with_model(self.modelfilter)
+         self.modelsort.connect("sort-column-changed", self.on_sort_column_changed)
+         self.modelsort.set_sort_func(sort_col, sort_func, sort_col)
+         self.sort_view(sort_key, sort_ascending)