Conflicting option definitions when adding an option to `zpool` datasets

[sylvorg]

Hello!

I'm trying to add a snapshot option to the zpool datasets, but can't because of a conflicting option definition:

error: The option `disko.devices.zpool.behemoth.datasets' in `/nix/store/27fy4ihy16233z2ipadgivvq2zkl69nn-source/common' is already declared in `/nix/store/0gqwnbivnyh3maw495r22l6k6d8bl9hd-source/lib/types/zpool.nix'.

Here's the entire option config:

{
  config,
  lib,
  ...
}:
{
  options.disko.devices.zpool =
    with lib;
    mkOption {
      type =
        with types;
        attrsOf (
          submodule (
            { name, config, ... }:
            {
              options.datasets = mkOption {
                type = attrsOf (
                  submodule (
                    {
                      name,
                      config,
                      options,
                      diskoLib,
                      ...
                    }:
                    {
                      options = {
                        snapshot = mkOption {
                          type = types.nullOr types.str;
                          default = null;
                          description = "The blank snapshot";
                        };
                        _create = diskoLib.mkCreateOption {
                          inherit config options;
                          default = ''
                            ${options._create.default}
                            ${optionalString (config.snapshot != null) ''
                              zfs snapshot ${config._name}@${config.snapshot}
                              zfs hold blank ${config._name}@${config.snapshot}
                            ''}
                          '';
                        };
                      };
                    }
                  )
                );
              };
            }
          )
        );
    };
}

I was under the assumption that the options would be merged automatically.

Any help would be greatly appreciated!

[sylvorg]

Here is an updated definition using diskoLib.subType:

{
  config,
  lib,
  inputs,
  ...
}:
with lib;
with types;
{
  options.disko.devices = mkOption {
    type = submodule (
      {
        name,
        config,
        ...
      }:
      {
        options.zpool = mkOption {
          type = attrsOf (
            inputs.disko.lib.subType {
              types.zpool =
                {
                  name,
                  config,
                  diskoLib,
                  ...
                }:
                {
                  options.datasets = mkOption {
                    type = attrsOf (
                      diskoLib.subType {
                        extraArgs.parent = config;
                        types.zfs_fs =
                          {
                            name,
                            config,
                            options,
                            diskoLib,
                            ...
                          }:
                          {
                            options = {
                              snapshot = mkOption {
                                type = types.nullOr types.str;
                                default = null;
                                description = "The blank snapshot";
                              };
                              _create = diskoLib.mkCreateOption {
                                inherit config options;
                                default = ''
                                  ${options._create.default}
                                  ${optionalString (config.snapshot != null) ''
                                    zfs snapshot ${config._name}@${config.snapshot}
                                    zfs hold blank ${config._name}@${config.snapshot}
                                  ''}
                                '';
                              };
                            };
                          };
                      }
                    );
                  };
                };
            }
          );
        };
      }
    );
  };
}