From 2d0f4a7ec19082248094eb04a35c93c94b1d35d5 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Fri, 1 Dec 2023 12:14:21 +0100
Subject: [PATCH] nixos/nix.nix: Support new Nix 2.20 command syntax

Otherwise it shows a deprecation warning, which is escalated to
an error. For context, see
https://github.com/NixOS/nixpkgs/pull/139075#discussion_r733615550
---
 nixos/modules/config/nix.nix | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/nixos/modules/config/nix.nix b/nixos/modules/config/nix.nix
index cee4f54db0cb..2769d8b25ef6 100644
--- a/nixos/modules/config/nix.nix
+++ b/nixos/modules/config/nix.nix
@@ -109,13 +109,17 @@ let
         if pkgs.stdenv.hostPlatform != pkgs.stdenv.buildPlatform then ''
           echo "Ignoring validation for cross-compilation"
         ''
-        else ''
+        else
+        let
+          showCommand = if isNixAtLeast "2.20pre" then "config show" else "show-config";
+        in
+        ''
           echo "Validating generated nix.conf"
           ln -s $out ./nix.conf
           set -e
           set +o pipefail
           NIX_CONF_DIR=$PWD \
-            ${cfg.package}/bin/nix show-config ${optionalString (isNixAtLeast "2.3pre") "--no-net"} \
+            ${cfg.package}/bin/nix ${showCommand} ${optionalString (isNixAtLeast "2.3pre") "--no-net"} \
               ${optionalString (isNixAtLeast "2.4pre") "--option experimental-features nix-command"} \
             |& sed -e 's/^warning:/error:/' \
             | (! grep '${if cfg.checkAllErrors then "^error:" else "^error: unknown setting"}')