Switch home configuration without rebuilding the system

[Nikola-Milovic]

I was wondering, what is the dynamic of home-manager with snowfall v3? I've read that in #7 standalone home manager is possible, my question is, how do I achieve this, and do I need to change anything in the modules themselves?

I currently have a system that enables option X. Then in my home manager modules depending on the osConfig.x i do different things, will this still work as indended? Since my system is systemA, and my home config is user@systemA I guess it should resolve correctly?

I have no issues with the current setup, it works wonderfully, I just dislike having to rebuild my entire system to get CSS change into my waybar, seems redundant. Are there any drawbacks to switching to standalone HM with snowfall?

[Nikola-Milovic]

It seems not possible at least with nh home switch

.dotfiles on  gammastep [+] ➜ nh home switch
warning: Git tree '/home/nikola/.dotfiles' is dirty
> Building home configuration
warning: Git tree '/home/nikola/.dotfiles' is dirty
error:
       … while evaluating a branch condition
         at /nix/store/ly4s3hw35dd1c2vsd694y2715pc1d2c1-source/lib/lists.nix:125:9:
          124|       fold' = n:
          125|         if n == len
             |         ^
          126|         then nul

       … while calling the 'length' builtin
         at /nix/store/ly4s3hw35dd1c2vsd694y2715pc1d2c1-source/lib/lists.nix:123:13:
          122|     let
          123|       len = length list;
             |             ^
          124|       fold' = n:

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: function 'anonymous lambda' called without required argument 'osConfig'
       at /nix/store/l76yhqhh85m3vw99xm438h4dfjvfvpb6-3wbl663mrnsi7fvdrqbyw7hizlspzgkj-source/modules/home/desktop/bars/waybar/default.nix:1:1:
            1| {
             | ^
            2|   config,
┏━ 1 Errors: 
┃ error:
┃        … while evaluating a branch condition
┃          at /nix/store/ly4s3hw35dd1c2vsd694y2715pc1d2c1-source/lib/lists.nix:125:9:
┃           124|       fold' = n:
┃           125|         if n == len
┃              |         ^
┃           126|         then nul
┃ 
┃        … while calling the 'length' builtin
┃          at /nix/store/ly4s3hw35dd1c2vsd694y2715pc1d2c1-source/lib/lists.nix:123:13:
┃           122|     let
┃           123|       len = length list;
┃              |             ^
┃           124|       fold' = n:
┃ 
┃        (stack trace truncated; use '--show-trace' to show the full, detailed trace)
┃ 
┃        error: function 'anonymous lambda' called without required argument 'osConfig'
┃        at /nix/store/l76yhqhh85m3vw99xm438h4dfjvfvpb6-3wbl663mrnsi7fvdrqbyw7hizlspzgkj-source/modules/home/desktop/bars/way…
┃             1| {
┃              | ^
┃             2|   config,
┣━━━                                                            
┗━ ∑ ⚠ Exited with 1 errors reported by nix at 08:22:53 after 0s
Error: 
   0: Command exited with status Exited(1)

Location:
   src/commands.rs:151

[jameslounds]

I've had a quick look at your nix-tmp repo, I think if you change your osConfig arguments to osConfig ? {}s (using an empty attest as the default argument), standalone should work - it works for my config at least.

Regarding the issue itself, I know home-manager switch accepts --options NAME VALUE, so maybe the nixos configuration could include a shell script which wraps home-manager switch to include certain values in an attrset at say config.${namespace}.osConfig using --option. No idea if this will work

For example in the nixosConfiguration somewhere

environment.systemPackages = [
  pkgs.writeShellScriptBin "hm-switch" ''
    home-manager switch --flake <path_to_your_flake> \ 
     --option ${namespace}.osConfig.services.myService.enable ${config.${namespace}.services.myService.enable}
     # and so on
  '';
];

[stratosgear]

Apologies for being so stupid. I have carefully read the thread but I do not understand the proposed usage here.... :(

First off: I have happily setup snowfall lib to properly manage multiple nixos installations (on desktops, laptops, cloud instances, etc) and it properly sets up my system AND my user (through homemanager), so that's fine.

My latest usecase is to now use the same flake on a brand new work laptop, that unfortunately has to have Ubuntu installed.

How can I use snowflake lib to only manage Home manager and install/configure that laptop with Home Manager alone?

What would be the incantation to deploy changes to my Ubuntu machine? Is there a sample repo where something like this is setup to take inspiration from?

Many thanks!!!

[stratosgear]

Thanks for your kind words and helpful steer in the right direction (actual direction, actually :) ).

Your suggestion worked fine and I can now configure my system with home-manager alone!

Thanks again!