Best practice for duplicated options between nixos and home-manager

[timboydon]

I've noticed that if I do my stylix configuration in configuration.nix then I don't have access to all the home-manager options/targets, however if I do my stylix configuration in home.nix, then I miss out on theming things like the bootloader and display manager.

I'm wondering then what is the best practice to avoid copy/pasting all the stylix configuration between the two files, as I'd like it to be easy to make changes and keep them in sync.

1. Do as much as possible in the configuration.nix and only use home.nix for options specific to home-manager (no code duplication, but would not be portable for non-nixos systems).
2. Keep everything in home.nix and only use configuration.nix for available system specific settings (all of the options in the configuration.nix would have to be updated in two places when making changes).
3. Define custom variables for things that will be used in both files (willing to learn if needed but was hoping to avoid unnecessary complexity).
4. Create a styilx-core.nix for options usable on both nixos and home-manager (imported into both configuration.nix and home.nix), as well as a stylix-home.nix for options specific to home-manager (imported only into home.nix).

Any thoughts on which approach makes the most sense here? I'm currently leaning towards the last option.

[danth]

The last option is what I've used in the past, when I used NixOS and Home Manager separately. I would recommend that.

I currently have Home Manager integrated into NixOS, which means I can write all the options in one file. This does mean it's not possible to use Home Manager on other distros any more.

When a module exists in both NixOS and Home Manager, it's always correct to enable both.
(Although only using one could be more optimal.)

[timboydon]

Thanks danth, I've gone ahead with the last approach as you suggested and all is working well.