From ad10d4fdef46a00bbe2d95aadc96b9e062fe0539 Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@shealevy.com>
Date: Sat, 29 Oct 2022 07:58:02 -0400
Subject: [PATCH] lib.modules.doRename: Don't define warning, even as
 undefined, if not warning.

This fixes mkAliasOptionModule in systems with no warning option.
---
 lib/modules.nix | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/modules.nix b/lib/modules.nix
index a7fbec93a2f5..204a2cc1ac12 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -1135,10 +1135,10 @@ rec {
         type = toType;
       });
       config = mkMerge [
-        {
+        (optionalAttrs (options ? warnings) {
           warnings = optional (warn && fromOpt.isDefined)
             "The option `${showOption from}' defined in ${showFiles fromOpt.files} has been renamed to `${showOption to}'.";
-        }
+        })
         (if withPriority
           then mkAliasAndWrapDefsWithPriority (setAttrByPath to) fromOpt
           else mkAliasAndWrapDefinitions (setAttrByPath to) fromOpt)