From 75efb8267438dd0788cef7573bb70e808a7b98f4 Mon Sep 17 00:00:00 2001
From: Daniel Fullmer <danielrf12@gmail.com>
Date: Thu, 12 May 2022 17:25:51 -0700
Subject: [PATCH] cudaPackages.cudnn: fix source fetching

Currently, cudaPackages_10_0.cudnn.src does not build, because passing
`hash = null;` to fetchurl causes it to try to fetch in the sandbox,
where it does not have internet access.
---
 pkgs/development/libraries/science/math/cudnn/generic.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkgs/development/libraries/science/math/cudnn/generic.nix b/pkgs/development/libraries/science/math/cudnn/generic.nix
index 1e9bac5efed2..a8a5ef084faf 100644
--- a/pkgs/development/libraries/science/math/cudnn/generic.nix
+++ b/pkgs/development/libraries/science/math/cudnn/generic.nix
@@ -21,12 +21,12 @@
 
 { fullVersion
 , url
-, hash ? null
-, sha256 ? null
+, hash ? ""
+, sha256 ? ""
 , supportedCudaVersions ? [ ]
 }:
 
-assert (hash != null) || (sha256 != null);
+assert (hash != "") || (sha256 != "");
 
 assert useCudatoolkitRunfile || (libcublas != null);