From 473ac9692e09451ef6025e50ccfa19efe5ae69a9 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 29 Jan 2023 23:39:27 +0100
Subject: [PATCH] lib.hydraJob: Tolerate null

By allowing null, we allow code to avoid filterAttrs, improving
laziness in real world use cases.
Specifically, this strategy prevents infinite recursion errors,
performance issues and possibly other errors that are unrelated to
the user's code.
---
 lib/customisation.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/customisation.nix b/lib/customisation.nix
index 101c9e62b9e6..42d711cf5fb9 100644
--- a/lib/customisation.nix
+++ b/lib/customisation.nix
@@ -252,7 +252,8 @@ rec {
       outputsList = map makeOutput outputs;
 
       drv' = (lib.head outputsList).value;
-    in lib.deepSeq drv' drv';
+    in if drv == null then null else
+      lib.deepSeq drv' drv';
 
   /* Make a set of packages with a common scope. All packages called
      with the provided `callPackage` will be evaluated with the same