From 7bb080c0e52eb4889af8e1c1b292a4803c5f791c Mon Sep 17 00:00:00 2001
From: Ben Wolsieffer <benwolsieffer@gmail.com>
Date: Wed, 29 Apr 2020 23:45:54 -0400
Subject: [PATCH] Test.hs: make sure to build the impure NVIDIA version
 derivation locally

---
 nixGL.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/nixGL.nix b/nixGL.nix
index 224fd9d..de18c01 100644
--- a/nixGL.nix
+++ b/nixGL.nix
@@ -32,6 +32,8 @@ let
         # To avoid sharing the build result over time or between machine,
         # Add an impure parameter to force the rebuild on each access.
         time = builtins.currentTime;
+        preferLocalBuild = true;
+        allowSubstitutes = false;
       }
       "cp /proc/driver/nvidia/version $out || touch $out";