Home-manager with a package from unstable

[voidzero]

Dear Misterio,

How do I install a package from unstable, in a home.nix file? Just one package, I prefer to keep the others at 22.05.

Previously I did it like this:

{ inputs, lib, config, pkgs, ... }:
let
  unstable = import <nixpkgs-unstable> { config = { allowUnfree = true; }; };
in
{
(...)

But this is considered impure in the world of flakes.

Sorry for my n00b question.

Mark

[voidzero]

My home-markvd.nix config (and my other config files) can be found here: https://github.com/voidzero/chopin/blob/master/dotfiles/home-manager/home-markvd.nix

[voidzero]

Also, for some reason I am getting the following message when running this command:

$ home-manager switch --flake '.#markvd@nixos-vmware'
warning: Git tree '/home/markvd/chopin' is dirty
trace: warning: You are using

  Home Manager version 22.11 and
  Nixpkgs version 22.05.

Using mismatched versions is likely to cause errors and unexpected
behavior. It is therefore highly recommended to use a release of Home
Manager than corresponds with your chosen release of Nixpkgs.

If you insist then you can disable this warning by adding

  home.enableNixpkgsReleaseCheck = false;

to your configuration.

But when I do home-manager --version the output is 22.05. Weird. Why is this happening?

[voidzero]

I bit the bullet and tried it with --impure. Now I get this:

$ home-manager switch --flake '.#markvd@nixos-vmware' --impure
trace: warning: You are using

  Home Manager version 22.11 and
  Nixpkgs version 22.05.

Using mismatched versions is likely to cause errors and unexpected
behavior. It is therefore highly recommended to use a release of Home
Manager than corresponds with your chosen release of Nixpkgs.

If you insist then you can disable this warning by adding

  home.enableNixpkgsReleaseCheck = false;

to your configuration.

error: attribute 'numbers' missing

       at /nix/store/rwlglfn25kylqr7sim7wkgqggnbcicii-source/modules/services/picom.nix:144:14:

          143|     activeOpacity = mkOption {
          144|       type = types.numbers.between 0 1;
             |              ^
          145|       default = 1.0;
(use '--show-trace' to show detailed location information)

At this point I feel like pulling out my hairs and giving up :sweat_smile:

[voidzero]

I asked on Reddit in this thread and got some very useful help. In particular the comment that we are close enough to NixOS and home-manager version 22.11 to use unstable made sense. So I have both the system and home-manager working properly now by using those versions - code can be seen here.

I am not yet sure what to do once 22.11 is the current version and I want to use a package from unstable after that. But at least I got the initial code to work, so that's nice.

[Misterio77]

Heyy, sorry for the wait; let me get you an example on how to do it.

[Misterio77]

Maybe this could be of help? https://github.com/Misterio77/nix-starter-configs/issues/4#issuecomment-1287903107

[voidzero]

Thanks! Ah okay, this would be for use with the standard - not minimal - flake setup. I should probably switch to the standard setup anyway because I plan to setup and manage other systems in my flake too some time in the future. Let me try this out and I'll get back on this. (Might take me a while, I am still recovering from covid and I am trying to learn NixOS and Flakes in between headaches :face_with_thermometer: )

[Misterio77]

I'm setting up a dual-nixpkgs template based on standard, I'll let you know when it's done. Shouldn't take long

Hope you get better soon!

[Misterio77]

Here's the template: https://github.com/Misterio77/nix-starter-configs/blob/main/multi-nixpkgs/flake.nix

In the example, I'm using unstable + master branches, but you may easily use 22.05 + unstable instead; the only thing to be aware is that home-manager.lib.homeManagerConfiguration's interface changed quite a bit from 22.05 to now.

First you add the extra input: https://github.com/Misterio77/nix-starter-configs/blob/main/multi-nixpkgs/flake.nix#L7

There's a lot of different ways to consume its packages (and modules, if you want); in this example I added the bleeding edge master packages as an overlay under the scope master, like so: https://github.com/Misterio77/nix-starter-configs/blob/main/multi-nixpkgs/overlays/default.nix#L6

You would then be able to access the master packages in your home configs like so:

{ pkgs, ... }: {
  home.packages = [
    pkgs.master.neofetch
    pkgs.pfetch
  ];
  programs.neovim.package = pkgs.master.neovim;
}

A repl example you can try out:

$ nix repl
Welcome to Nix 2.11.0. Type :? for help.

nix-repl> :lf github:misterio77/nix-starter-configs?dir=multi-nixpkgs
Added 16 variables.

nix-repl> pkgs = homeConfigurations."your-username@your-hostname".pkgs

nix-repl> pkgs.flow
«derivation /nix/store/jimkg20hpc9mdy51wgxs9b5fwnmi16vl-flow-0.191.0.drv»

nix-repl> pkgs.master.flow
«derivation /nix/store/7lx0khm8kkbix197hp70cdzd3fxp3ymd-flow-0.192.0.drv»

You can alternatively:

• Instantiate nixpkgs-master directly on the flake and pass it as a specialArg/extraSpecialArg to your config. You would then access it like an alternative pkgs argument, maybe pkgsMaster or something like that.
• Instead of overlaying the entire master package set as a scope inside your regular pkgs, you can overlay individual packages with their master counterpart. I'm not a big fan of this, as it has the chance of overriding dependencies of other packages (e.g. bar depends on foo 0.1, but you override it with foo 0.2, breaking bar unless you also override bar).

[voidzero]

Alright, a lot for me to try out, thank you. First I'll modify my config and will have this ready in a few minutes.

I notice in the multi-nixpkgs/flake.nix we are not setting config.allowUnfree anymore. Where should I add this now? edit never mind, I see it already (./nixpkgs-config.nix)

[Misterio77]

I've moved it to nixpkgs-config.nix with https://github.com/Misterio77/nix-starter-configs/pull/7

[Misterio77]

TLDR: Instantiating nixpkgs right on the flake and passing it to the configs is not good practice; it's better to use nixpkgs.* options.

So I created a file that has common configuration we import on both home-manager and nixos, that way we have a centralized way to apply overlays and set options (such as allowUnfree), while avoiding the issues we would have instantiating nixpkgs directly.

[voidzero]

At first I got the following error:

$ sudo nixos-rebuild switch --flake '.#nixos-vmware'
error: value is a function while a set was expected

       at /nix/store/zz9rbrbh8jmkdnsn83qc67ywkbbcjj12-source/nixpkgs-config.nix:8:16:

            7|     # Overlays is an attrset, convert to a list
            8|     overlays = builtins.attrValues overlays;
             |                ^
            9|   };

It makes me guess that we don't need to convert overlays to a list, so I removed that line. I also had to add system="x86_64-linux"; under the hostname under nixosConfigurations in my flake.nix (because I am using 22.05 I suppose?)

The system now builds, and I have pushed my updates to the master branch of https://github.com/voidzero/chopin. This is using multi-nixpkgs now.

home-manager does not build, probably because there are differences between 22.05 and 22.11? First it complains about no argument system in homeConfigurations. So I added it there too. Now it complains about the following:

$ home-manager switch --flake '.#markvd@nixos-vmware'                             
error: 'homeManagerConfiguration' at /nix/store/zjxmj1b43j32zkvj1821a59svfgsknbg-source/flake.nix:44:36 called without required argument 'configuration'

       at /nix/store/72qczrd6qnqmvix2ih7947kia5yah607-source/flake.nix:69:33:

           68|         # FIXME replace with your username@hostname
           69|         "markvd@nixos-vmware" = home-manager.lib.homeManagerConfiguration {
             |                                 ^
           70|           system = "x86_64-linux";

Hope you are not getting tired of me yet 😅

[Misterio77]

Hey,

So I removed that line. I also had to add system="x86_64-linux"; under the hostname under nixosConfigurations in my flake.nix (because I am using 22.05 I suppose?)

Yup, that's right.

It makes me guess that we don't need to convert overlays to a list

In your case, yeah. The newer update changed overlays/default.nix to an attribute set of overlays, but your is simply a single (composed) overlay, so no need to convert it. Just change the line to: overlays = [ overlays ]. Nixpkgs expectes overlays to be a list of overlays.

Do keep in mind that the overlays output in the flake is supposed to be an attrset of overlays, so, if prefer to keep overlays/default.nix the way it is, change this line to:

 overlays.default = import ./overlays { inherit inputs; };

If you do, nixpkgs-config.nix's overlays = builtins.attrValues overlays; should work as expected.

$ home-manager switch --flake '.#markvd@nixos-vmware'
error: 'homeManagerConfiguration' at /nix/store/zjxmj1b43j32zkvj1821a59svfgsknbg-source/flake.nix:44:36 called without required argument 'configuration'

Yeah, the homeManagerConfiguration function changed quite a bit from 22.05 to 22.11/unstable, so you must match it. I can't seem to find the 22.05 release hm manual, but here's the function definition: https://github.com/nix-community/home-manager/blob/release-22.05/flake.nix#L44, should help you out.

Hope you are not getting tired of me yet sweat_smile

Don't worry! Not a problem at all. I might take a few mins to a few hours to respond, though.

[voidzero]

Alright, a real head scratcher. With regards to 22.05 it looks like the homeManager configuration is weirdly different for when it is in a flake or when it is in a home.nix. Because in home.nix, you can set things like home.username, home.homeDirectory, but in the flake you have to configure these separately as well.

I changed the code in flake.nix to the following, just to test:

homeConfigurations = { 
  "markvd@nixos-vmware" = home-manager.lib.homeManagerConfiguration {
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.x86_64-linux;
    extraSpecialArgs = { inherit inputs; };
    configuration = ./home-manager/home-markvd.nix;
    homeDirectory = "/home/markvd";
    username = "markvd";
  };  
};

Now I run:

$ home-manager --version                                          
22.05

$ home-manager switch --flake '.#markvd@nixos-vmware'             
warning: Git tree '/home/markvd/chopin' is dirty
error: The option `home.stateVersion' has conflicting definition values:
       - In `/nix/store/crzflhwq1jgh9giga32d77dm41y2alfj-source/home-manager/home-markvd.nix': "22.05"
       - In `<unknown-file>': "20.09"
(use '--show-trace' to show detailed location information)

I have no idea where 20.09 comes from.

[Misterio77]

You should set stateVersion on the flake function call as well https://github.com/nix-community/home-manager/issues/2073.

homeConfigurations = { 
  "markvd@nixos-vmware" = home-manager.lib.homeManagerConfiguration {
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.x86_64-linux;
    extraSpecialArgs = { inherit inputs; };
    configuration = ./home-manager/home-markvd.nix;
    homeDirectory = "/home/markvd";
    username = "markvd";
    stateVersion = "22.05";
  };  
};

[voidzero]

That works and now we are on the next problem: when home-markvd.nix contains vivaldi, I get a complaint about a missing allowUnfree. Apparently there is a bug about the allowUnfree issue described here: https://github.com/nix-community/home-manager/issues/2942.

I have added allowUnfreePredicate = (_: true); in nixpkgs-config.nix, and this makes vivaldi (the stable version) work.

I also found that I can use extraModules in homeConfigurations, so I added this to use the unstable overlay there. My config now looks as follows:

homeConfigurations = {
  "markvd@nixos-vmware" = home-manager.lib.homeManagerConfiguration {
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.x86_64-linux;
    extraSpecialArgs = { inherit inputs; };
    configuration = ./home-manager/home-markvd.nix;
    homeDirectory = "/home/markvd";
    username = "markvd";
    stateVersion = "22.05";
    extraModules = (builtins.attrValues homeManagerModules) ++ [
      (import ./nixpkgs-config.nix { inherit overlays; })
    ];
  };
};

Now I can change vivaldi to vivaldi-unstable, and I see that it will try to install the correct version of vivaldi, but, here it still complains about allowUnfree. So it is not reading the allowUnfreePredicate option either, meaning that I cannot install vivaldi-unstable. This is where I am stuck.

[Misterio77]

I think you'll need to instantiate nixpkgs-unstable with allowUnfree true, this should do the trick: https://github.com/voidzero/chopin/pull/1

[voidzero]

@Misterio77 you're my hero! This works! I can now run this flake without impure, and it installs the packages from unstable. Much thanks!! :+1: :+1:

[Misterio77]

You're very welcome :)

[voidzero]

Maybe beyond the issue but just for my education, how did you learn this solution?

[Misterio77]

It's just something I came to the conclusion to, after knowing a bit about how nix and nixpkgs work. It's a little hard to enumerate which resources I used to get to know them, but I'd recommend you read nix pills; there's a lot of other good guides at the NixOS.org learn page, as well.

[voidzero]

Will do. Thanks again. I'll close this bug. :rose: