From ab070d1b0b424a49322d70a75b21c4f21e10637a Mon Sep 17 00:00:00 2001
From: Joachim Fasting <joachifm@fastmail.fm>
Date: Sun, 6 Jan 2019 19:28:35 +0100
Subject: [PATCH] nixos/opengl: assert 32bit emu support if 32bit support is
 enabled

See https://github.com/NixOS/nixpkgs/issues/51097
---
 nixos/modules/hardware/opengl.nix | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/nixos/modules/hardware/opengl.nix b/nixos/modules/hardware/opengl.nix
index 48e0072e0892..6b7b8069fd44 100644
--- a/nixos/modules/hardware/opengl.nix
+++ b/nixos/modules/hardware/opengl.nix
@@ -124,10 +124,14 @@ in
 
   config = mkIf cfg.enable {
 
-    assertions = lib.singleton {
-      assertion = cfg.driSupport32Bit -> pkgs.stdenv.isx86_64;
-      message = "Option driSupport32Bit only makes sense on a 64-bit system.";
-    };
+    assertions = [
+      { assertion = cfg.driSupport32Bit -> pkgs.stdenv.isx86_64;
+        message = "Option driSupport32Bit only makes sense on a 64-bit system.";
+      }
+      { assertion = cfg.driSupport32Bit -> (config.boot.kernelPackages.kernel.features.ia32Emulation or false);
+        message = "Option driSupport32Bit requires a kernel that supports 32bit emulation";
+      }
+    ];
 
     systemd.tmpfiles.rules = [
       "L+ /run/opengl-driver - - - - ${package}"