stylix nixos module assumming home-manager useage in nixos about stylix

[danth]

It seems that when we use mkIf, the option must exist even if the condition is false. Something like optionalAttrs would fix that, but it might introduce new issues which mkIf exists to solve.

[dwarfmaster]

I looked into it, and it seems we're running into a limitation of the nixos module system. We can't conditionally set an option only if it exists. The following in stylix/nixos/default.nix should work, but it will break for any config in which computing the WHNF of options depends on the WHNF of config :

   if options ? home-manager
    then (lib.mkIf hm.autoImport {
           home-manager.sharedModules = [ homeManagerModule ];
         })
    else {}

[SenchoPens]

Hi everyone!

@dwarfmaster the WHNF of options can't depend on the WHNF of config in first place as it will cause infinite recursion right away, because the WHNF of config depends on the WHNF of options, so it's safe to do as you proposed.

@danth maybe follow this pattern for modules which set options that are not in the latest release? I just tried it on my local fork with avizo and mako, while being on 22.11, and it worked. Example (mako.nix):

...
  config = if options.services ? mako then lib.mkIf config.stylix.targets.mako.enable {
...

[SomeGuyNamedMay]

that seems like a reasonable option to me

[danth]

@SenchoPens That makes sense, I can implement it unless you're already working on it (I noticed you forked the repo).

Is it safe to use lib.optionalAttrs in place of the if statement?

[SenchoPens]

Done. Good call with the lib.optionalAttrs!