Arul Agrawal (Dec 08 2025 at 13:32): Arul Agrawal (Dec 08 2025 at 13:32):Hey all, I recently tried to update my system nix flake after a few months, and ran into an issue I haven't been able to find much about:
419| The module `${m._file or m.key}` (class: ${lib.strings.escapeNixString m._class}) cannot be imported into a module evaluation that expects class ${lib.strings.escapeNixString class}.
error: The module `/nix/store/xm3nq4fadri4jcc3ms6vhc4nx5rgi27z-source/flake.nix#nixosModules.common` (class: "nixos") cannot be imported into a module evaluation that expects class "darwin".
Help:
- Ensure that you are importing the correct module.
- Verify that the module's `_class`, "nixos" matches the expected `class` "darwin".
- If you are using a custom class, make sure it is correctly defined and used consistently across your modules.
Here is my current flake: https://github.com/arulagrawal/nix/blob/fixing/flake.nix
The only thing I did was run nix flake update (no config changes) so I'm not really sure where things changed.
Any help appreciated!!
Srid (Dec 08 2025 at 17:43):Probably coming from new flake-parts.
Don't run nix flake update. Instead only update the relevant inputs (nixpkgs, nix-darwin, home-manager, etc.) by passing them as arguments.
Srid (Dec 08 2025 at 17:46):And since you use nixos-unified:
Last updated: Dec 25 2025 at 08:28 UTC