From 5157fbaf2cd7eaaa5236801c2f4b409a6f5404df Mon Sep 17 00:00:00 2001
From: Tom Hubrecht <github@mail.hubrecht.ovh>
Date: Wed, 10 Dec 2025 17:10:30 +0100
Subject: [PATCH] testWithNix: Don't depend on CppNix

Change-Id: Ia0903d93796c30e370d99d02877cc93c258b8f32
---
 flake.nix | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/flake.nix b/flake.nix
index 6d982b1f0..59d910cd1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -465,7 +465,20 @@
               let
                 inherit (self.packages.${system}) nix;
                 pkgs = nixpkgsFor.${system}.native;
-                testWithNix = import (nixpkgs + "/lib/tests/test-with-nix.nix") { inherit pkgs lib nix; };
+                testWithNix =
+                  (import (nixpkgs + "/lib/tests/test-with-nix.nix") {
+                    inherit pkgs lib nix;
+                  }).overrideAttrs
+                    (_: {
+                      buildInputs = [
+                        (import (nixpkgs + "/lib/path/tests") {
+                          inherit pkgs;
+                          # NOTE: Override the nix version used here, we cannot rely on CppNix actually building
+                          #       c.f. https://github.com/NixOS/nixpkgs/blob/master/lib/path/tests/default.nix#L18
+                          nixVersions.stable = nix;
+                        })
+                      ];
+                    });
               in
               pkgs.symlinkJoin {
                 name = "nixpkgs-lib-tests";