warning: input 'nixCats' has an override for a non-existent input 'nixpkgs'

[Sapp00]

Hi,

I want to use nvim 11.x, so I wanted to make nixCats follow the unstable channel just as I would do for other flakes.

    nixCats = {
      url = "github:BirdeeHub/nixCats-nvim";
      inputs.nixpkgs.follows = "nixpkgs-unstable";
    };

It is also kind of the same as you did in your template: https://github.com/BirdeeHub/nixCats-nvim/blob/main/templates/overriding/flake.nix

Unfortunately, this does not work as I get the following warning during rebuild:
warning: input 'nixCats' has an override for a non-existent input 'nixpkgs'

[BirdeeHub]

nixCats has no flake inputs.

There is no nixpkgs to override. The warning is correct. non-existent input indeed.

It uses the nixpkgs you pass where you call the utils.baseBuilder function. So you can just pass it whatever nixpkgs you wish. If you are using the module, the nixpkgs_version option does the same.

nixCats is a no-dependency library which contains a builder function that may receive a nixpkgs or pkgs to use.

[BirdeeHub]

in the overriding template (which is actually more of a tutorial than a template to be honest and should probably have a readme), it is importing an already existing configuration, (the example template's configuration) which does have a nixpkgs.

Note the URL here

nixCats-nvim/templates/overriding/flake.nix

Lines 15 to 16 in e94f31a

	nixCats.url = "github:BirdeeHub/nixCats-nvim?dir=templates/example";
	nixCats.inputs.nixpkgs.follows = "nixpkgs";

And we can see that the flake of the example template does have a nixpkgs

nixCats-nvim/templates/example/flake.nix

Lines 24 to 28 in e94f31a

	inputs = {
	nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
	nixCats.url = "github:BirdeeHub/nixCats-nvim";
	# see :help nixCats.flake.inputs

But the base nixCats flake that outputs just the nixCats library with the builder in it has no flake inputs whatsoever.

nixCats-nvim/flake.nix

Lines 1 to 22 in e94f31a

	# Copyright (c) 2023 BirdeeHub
	# Licensed under the MIT license
	{
	description = ''
	# nixCats - nix categories for neovim #
	A neovim package manager written in nix, with normal neovim directory structure,
	easy communication from nix to your neovim configuration,
	and ability to simply categorize dependencies for outputting multiple packages.
	'';
	outputs = _: let
	# everything you will need is in utils.
	utils = import ./utils;
	nixosModule = utils.mkNixosModules {};
	homeModule = utils.mkHomeModules {};
	in {
	inherit utils homeModule nixosModule;
	inherit (utils) templates;
	nixosModules.default = nixosModule;
	homeModules.default = homeModule;
	};
	}

[BirdeeHub]

so yeah if you were wondering how the nixCats-nvim repo has no top level flake.lock, that is why. It has nothing to lock.

utils/default.nix relies only on the builtin functions in nix to import and thus there is no required nixpkgs input.

This is also how it works well with or without flakes despite not using flake-compat

[BirdeeHub]

in the default template, the main builder function is called here

nixCats-nvim/templates/fresh/flake.nix

Lines 206 to 209 in e94f31a

	nixCatsBuilder = utils.baseBuilder luaPath {
	inherit nixpkgs system dependencyOverlays extra_pkg_config;
	} categoryDefinitions packageDefinitions;
	defaultPackage = nixCatsBuilder defaultPackageName;

and in the flakeless one, here

nixCats-nvim/templates/flakeless/default.nix

Line 121 in e94f31a

in utils.baseBuilder luaPath { inherit pkgs; } categoryDefinitions packageDefinitions defaultPackageName

and the modules call it for you.

And here are the docs for it https://nixcats.org/nixCats_utils.html#function-library-nixCats.utils.baseBuilder

That is what defines the pkgs that pkgs.neovim-unwrapped gets pulled from by default (although you can also set neovim-unwrapped settting in your packageDefinitions!)

It is also what controls the pkgs provided to your packageDefinitions and your categoryDefinitions

Unless you pass in a pkgs directly, (in which case, that will be used directly if possible), nixCats will resolve a pkgs for you from the nixpkgs you provide.

In this way, nixCats can work with a variety of nix implementations, such as lix and tvix, and a variety of nixpkgs versions and implementations as well!

[Sapp00]

Ahh, now I got it thank you! I didn't spot that you have been referencing the example config.
Also thank you for explaining the details as I am still exploring nix.

That is what defines the pkgs that pkgs.neovim-unwrapped gets pulled from by default (although you can also set neovim-unwrapped settting in your packageDefinitions!)

got it! worked around it by setting neovim-unwrapped to the unstable channel:

      packageDefinitions.replace = {
        myHomeModuleNvim = {pkgs , ... }: {
          settings = {
            neovim-unwrapped = pkgs.unstable.neovim-unwrapped;

[BirdeeHub]

I see you are using the module!

Yeah if you only want to upgrade nvim and nothing else, setting neovim-unwrapped is the right way to do that.

If you wish to pull lsps and plugins and all the rest from unstable there are more options as well.

You can set nixpkgs_version option to set the nixpkgs that the pkgs provided to your packageDefinitions and categoryDefinitions comes from

That would mean the pkgs in myHomeModuleNvim = {pkgs , ... }: { and the pkgs provided to your categoryDefinitions as well! (the name myHomeModuleNvim is totally arbitrary by the way you can change that, just make sure the ones you are installing via packageNames options match!)