hi. i've been trying to update a flake-based nixos system on a machine with no internet access. for the last week i've been successfully doing it like so:

laptop$ # this host has internet connection
laptop$ nix copy --to /path/to/usb/drive/ \
  .#nixosConfigurations.offlineHost.config.system.build.toplevel

offlineHost$ # this host has no network connection
offlineHost$ nix copy --all --from /path/to/usb/drive/
offlineHost$ nixos-rebuild switch --flake /path/to/flake

this worked well until today, as now the nixos-rebuild command fails because it wants to fetch archives from github :(

i've tried all the tricks from the various threads about this, but i've had no luck. i'm now surprised it even worked at all. now i have a system that i can no longer update

then i saw this lix issue and now i have some hope:
https://git.lix.systems/lix-project/lix/issues/116

i'm currently checking out lix to see if it might be more suited for use on an offline machine.

does anyone here have any experience or advice for me? :)

thank you K900! i will try this. how would i find the correct switch-to-configuration script on the airgapped machine? assuming i follow the steps above (except nixos-rebuild), i have several switch-to-configuration files and i'm not sure which is the one i want to run:

$ ls /nix/store/*nixos-system-offlineHost*/bin/switch-to-configuration
/nix/store/8f7m0wgws72gichxrmmvy9fbz5zpxhsb-nixos-system-offlineHost-24.11.20241213.314e12b/bin/switch-to-configuration
/nix/store/8zg49xpy4jiqspby1bwl7l5d9m6xrf5s-nixos-system-offlineHost-24.11.20241213.314e12b/bin/switch-to-configuration
/nix/store/ip9qcm6jv85d370jqhycd5lbivfcyddy-nixos-system-offlineHost-24.11.20241130.62c435d/bin/switch-to-configuration
/nix/store/kqag8sacazr1sww6b1xwdl7kawj9dmsh-nixos-system-offlineHost-24.11.20241213.314e12b/bin/switch-to-configuration

aha, it tells me on the nix copy command:

copying path '/nix/store/lwl9s80fm08r4ma8m3lkssx75bv9qq3a-nixos-system-thebox-24.11.20241213.314e12b' to 'local'...

i can then run /nix/store/lwl9s80fm08r4ma8m3lkssx75bv9qq3a-nixos-system-thebox-24.11.20241213.314e12b/bin/switch-to-configuration switch

aha, it tells me on the nix copy command:

copying path '/nix/store/lwl9s80fm08r4ma8m3lkssx75bv9qq3a-nixos-system-thebox-24.11.20241213.314e12b' to 'local'...

i can then run /nix/store/lwl9s80fm08r4ma8m3lkssx75bv9qq3a-nixos-system-thebox-24.11.20241213.314e12b/bin/switch-to-configuration switch

    boot.loader = {
      timeout = 0;
      efi.canTouchEfiVariables = true;
      systemd-boot = {
        enable = true;
        configurationLimit = 5; # Prevent infinite generations filling up /boot
      };
    };

In reply to @k900:0upti.me
That should update the bootloader config

In reply to @dxmh:matrix.org
the discussion in the link above (from 2020-2024) does suggest that switch-to-configuration switch doesn't work as it suggests. is there another way to update the bootloader config?