Yeah, for this usecase, I'd recommend putting the namespace in the file name rather than dir since with dirs its different in the filesystem and the nix code. nix flake show or nix eval .#nixosModules --apply __attrNames would show all of them without namespacing. IMO making it .#nixosModules.desktops-gnome.nix would be more descriptive.

though if you want that layout, i'd set nixDirAliases.nixosModules = [ "nixos/modules" ] and then have nixos/modules/default.nix be:

{flakelight, lib, ...}:
lib.pipe ./. [
  builtins.readDir
  (lib.filterAttrs (_: v: v == "directory")
  lib.attrNames
  (map (d: flakelight.importDir (./. + d)))
  (lib.foldr (a: b: a // b) {})
] 

I'm not sure how the glob would match in general, and what to do about matching files etc. I think this case would be good to specify how it should be loaded.

I guess the idea is just to use directories to better organize modules.

Your suggestion with using default.nix is the exact thing I want to minimize and ideally avoid.
It is hard to read for users without any Nix experience (I really try to keep the Nix files simple, so they are primarily declarative), and again it is boilerplate, that ideally it could be fully avoided with e.g. the wildcard feature.

I guess the idea is just to use directories to better organize modules.

Your suggestion with using default.nix is the thing I want to minimize and ideally avoid.
It is hard to read for users without any Nix experience (I really try to keep the Nix files simple, so they are primarily declarative), and again it is boilerplate, that ideally it could be fully avoided with e.g. the wildcard feature.

I guess the developer's idea is to use the directories to categorize modules.

Your suggestion with using default.nix is the thing I want to minimize and ideally avoid.
It is hard to read for users without any Nix experience (I really try to keep the Nix files simple, so they are primarily declarative), and again it is boilerplate, that ideally it could be fully avoided with e.g. the wildcard feature.

I guess the developer's idea is to use the directories to categorize modules.

Your suggestion with using default.nix is the thing I want to minimize and ideally avoid.
It is hard to read for users without any Nix experience (I really try to keep the Nix files simple, so they are primarily declarative), and again it is boilerplate, that ideally could be avoided with e.g. the wildcard feature.

maybe it would work to have a common nix lib provide a lib glob function?

though using nixDirAliases.nixosModules = lib.pipe ./nixos/modules [ builtins.readDir lib.attrNames (map (d: "nixos/modules/${d}"))] would be less code than pulling in a lib if thats all thats in it

How can you access lib here?:

nixDirAliases = {
  nixosModules = lib.subdirs "nixos/modules"
};

The idea is to have something that is easy to read for non-Nix native developers.

Compare this:

nixDirAliases = {
  nixosModules = [ "nixos/modules/*" ]
};

To this:

nixDirAliases = {
  nixosModules = lib.pipe ./nixos/modules [ builtins.readDir lib.attrNames (map (d: "nixos/modules/${d}"))] 
};

For how easy it is to read for someone, who has never programmed a ml-like language.

Is withOverlays not applied in nixosConfigurations?

I have added the function lib.noverby.add to withOverlay, but the function cannot be accessed?

nixosConfigurations/gravitas.nix:

Is withOverlays not applied in nixosConfigurations?

I have added the function lib.noverby.add to withOverlay, but the function cannot be accessed?

devices/gravitas.nix: (nixosConfigrations has an alias to devices)

Is it possible to add functions to ModuleArgs.lib?

I need it to create helper functions for setting up nixosConfigrations.
It seems like it cannot be added using withOverlays, is there another approach?