error:
       … while evaluating the attribute 'drvPath'
         at «https://releases.nixos.org/nixpkgs/nixpkgs-26.11pre1100901.d3b13ad75cc4/nixexprs.tar.zst?narHash=sha256-lrp%2BA0ZwQN3V0tSZP6vVFIX/16FFOzr19mSup8XD80w%3D»/lib/customisation.nix:420:11:
          419|         // {
          420|           drvPath =
             |           ^
          421|             assert condition;

       … while calling the 'derivationStrict' builtin
         at «nix-internal»/derivation-internal.nix:37:12:
           36|
           37|   strict = derivationStrict drvAttrs;
             |            ^
           38|

       … while evaluating the option `driverConfiguration.vms.machine.start_script':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/lib/testing/driver-configuration.nix':

       … while evaluating the option `nodes.machine.system.build.toplevel':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/modules/system/activation/top-level.nix':

       … while evaluating the option `nodes.machine.assertions':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/modules/tasks/filesystems/zfs.nix':

       … while evaluating the option `nodes.machine.boot.zfs.enabled':

       … while evaluating the option `nodes.machine.boot.initrd.supportedFilesystems':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/modules/system/boot/stage-1.nix':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/modules/tasks/filesystems.nix':

       … while evaluating the option `nodes.machine.fileSystems."/bin".device':

       … while evaluating definitions from `/nix/store/5kch26ml22zg5gx0gym9nff7j5rificm-source/nixos/modules/tasks/filesystems.nix':

       … while evaluating the option `nodes.machine.fileSystems."/bin".fsType':

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

       error: The option `nodes.machine.fileSystems."/bin".fsType' was accessed but has no value defined. Try setting the option.