Infinite recursion encountered

[robertodr]

I've been trying to update my flake setup to use the latest version of stylix, but I keep hitting an infinite recursion:

error: infinite recursion encountered

       at /nix/store/f6jk9gi6i92ngcbkcz8z2d7gvkksciw1-source/lib/modules.nix:728:9:

          727|     in warnDeprecation opt //
          728|       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
             |         ^
          729|         inherit (res.defsFinal') highestPrio;
(use '--show-trace' to show detailed location information)

Using --show-trace doesn't help much in finding the reason unfortunately.
This is the latest revision of stylix that works for me: d7536947a7fc3f9b60ba3c8f19c2530ca00110a9. I'm using digga to structure my configuration (you can find it here) I define the theme in this file which I then import in the definition of the user

[dwarfmaster]

I'm trying to reproduce your problem, how should I build your config ? I've tried a nix flake show but I get an error when evaluatiing checks.

[robertodr]

I usually use nixos-rebuild: sudo nixos-rebuild --flake .#captain-easychord build

[dwarfmaster]

Ok so after some experimentation, there are two things that both cause infinite recursion, but I don't yet know why:

• In stylix/nixos/palette.nix, setting stylix/palette.html (that one actually works)
• In modules/gnome/nixos.nix, setting the overlay

[dwarfmaster]

In modules/gnome/nixos.nix, even setting nixpkgs.overlays to [] cause the infinite recursion, but setting it from stylix/nixos/default.nix does not cause any trouble. So it might be something linked to the interaction of nixpkgs.overlays and mkIf. However, I didn't encounter this problem on my config, it probably is linked to something digga is doing.

[dwarfmaster]

Ok so my hypothesis is that digga use the value of nixpkgs.overlays and nixpkgs.pkgs to build the lib argument it gives to the modules (I don't have the time right now to dive into the implementation details of digga to make sure of that). That means that anything using lib needs first to evaluate config.nixpkgs.overlays, which in our case need to evaluate lib.mkIf, creating the infinite recursion.
That would explain why I haven't encountered this bug, since my lib argument comes from outside the module system.
I am not sure how to fix it however, I would have to think a bit more about it.

[dwarfmaster]

I confirmed that if the mkIf comes from outside, there is no more infinite recursion, but I'm not sure how to do that properly.
Maybe it would be best if we simply avoided setting nixpkgs.overlays, since anyway the user may discard it by passing pkgs as an argument to nixosSystem. @danth do you think it would be possible to theme gnome without it ?

[robertodr]

Thank you so much for digging through this! Would opening an issue on the digga repository help?

[dwarfmaster]

Maybe that's the best thing to do indeed. I will create a FAQ here in case someone else encounters the same problems, because it is not specific to digga.

[danth]

do you think it would be possible to theme gnome without it ?

Once logged in, yes, but I couldn't find any other way to theme GDM as it doesn't load extensions.