`nixos-generate-config --show-hardware-config` fails after `disko-install`

[font44]

Hi,

I followed https://github.com/nix-community/disko/blob/master/docs/disko-install.md#fresh-installation to setup a fresh system and it went through successfully.

My hardware-configuration.nix though doesn't contain any fileSystems or LUKS encryption configuration. See: https://github.com/font44/nixos-config/blob/main/hardware-configuration.nix

Moreover, I see the following failure while trying to regenerate that file:

user@nixos:/tmp/ > nixos-generate-config --show-hardware-config
Failed to retrieve subvolume info for /

Is this expected? Is there any workaround by which I can add fileSystems and boot.initrd.luks.devices entries to my hardware-configuration.nix or make the nixos-generate-config command succeed?

[Mic92]

Usually you would import the disko module and give it the configuration you used for partitioning. In the documentation you referenced we do nixos-generate-config --no-filesystems instead.

[font44]

Yes, that's how I did it: https://github.com/font44/nixos-config/blob/main/flake.nix#L51 and it worked during installation. nixos-rebuild switch --flake .#machine is also fine, it's just that nixos-generate-config --show-hardware-config doesn't work anymore and I am worried if that will cause problems for me down the line. (For example, if I change GPU or install new disks.)

Any way to fix this?