From cb289a9256254d00e147521388093468eaf202cb Mon Sep 17 00:00:00 2001
From: Maximilian Bosch <maximilian@mbosch.me>
Date: Sat, 9 Dec 2023 11:57:56 +0100
Subject: [PATCH] flake: be backwards-compatible for `--impure`

We cannot pass `overlays = ...` to `nixpkgs` directly because by default
overlays from `~/.config/nixpkgs` are loaded in there. This doesn't
happen by default, but when using `--impure`.

Explicitly specifying that ignores these overlays. By using `pkgs.extend`
the old behavior can be kept and the new overlay can be applied.

Co-authored-by: Silvan Mosberger <contact@infinisil.com>
---
 flake.nix | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/flake.nix b/flake.nix
index 307eea0cd040..9b437c169a4f 100644
--- a/flake.nix
+++ b/flake.nix
@@ -52,10 +52,9 @@
       # attribute it displays `omitted` instead of evaluating all packages,
       # which keeps `nix flake show` on Nixpkgs reasonably fast, though less
       # information rich.
-      legacyPackages = forAllSystems (system: import ./. {
-        inherit system;
-        overlays = [ self.overlays.setLibVersionInfo ];
-      });
+      legacyPackages = forAllSystems (system:
+        (import ./. { inherit system; }).extend self.overlays.setLibVersionInfo
+      );
 
       nixosModules = {
         notDetected = ./nixos/modules/installer/scan/not-detected.nix;