anchor.diff:            }
             cfg.service
             c.service
  -        ])) cfg.commands;
  -    };
  -
  -    meta.maintainers = with maintainers; [ julm lopsided98 ];
  -  }
  +        ]))
  +      cfg.commands;
  +  };
  +
  +  meta.maintainers = with maintainers; [ julm lopsided98 ];
  +}
  
positive.code:   # Extract local dasaset names (so no datasets containing "@")
    localDatasetName = d: optionals (d != null) (
      let m = builtins.match "([^/@]+[^@]*)" d; in
      optionals (m != null) m);
  
    # Escape as required by: https://www.freedesktop.org/software/systemd/man/systemd.unit.html
    escapeUnitName = name:
      lib.concatMapStrings (s: if lib.isList s then "-" else s)
      (builtins.split "[^a-zA-Z0-9_.\\-]+" name);
  
    # Function to build "zfs allow" and "zfs unallow" commands for the
    # filesystems we've delegated permissions to.
    buildAllowCommand = zfsAction: permissions: dataset: lib.escapeShellArgs [
      # Here we explicitly use the booted system to guarantee the stable API needed by ZFS
      "-+/run/booted-system/sw/bin/zfs" zfsAction
      cfg.user (concatStringsSep "," permissions) dataset
    ];
  in {
  
      # Interface
  
      options.services.syncoid = {
        enable = mkEnableOption "Syncoid ZFS synchronization service";
  
        interval = mkOption {
          type = types.str;
          default = "hourly";
          example = "*-*-* *:15:00";
          description = ''
            Run syncoid at this interval. The default is to run hourly.
  
            The format is described in
            <citerefentry><refentrytitle>systemd.time</refentrytitle>
            <manvolnum>7</manvolnum></citerefentry>.
          '';
        };
  
        user = mkOption {
          type = types.str;
          default = "syncoid";
          example = "backup";
          description = ''
            The user for the service. ZFS privilege delegation will be
            automatically configured for any local pools used by syncoid if this
            option is set to a user other than root. The user will be given the
            "hold" and "send" privileges on any pool that has datasets being sent
            and the "create", "mount", "receive", and "rollback" privileges on
            any pool that has datasets being received.
          '';
        };
  
        group = mkOption {
          type = types.str;
          default = "syncoid";
          example = "backup";
          description = "The group for the service.";
        };
  
        sshKey = mkOption {
          type = types.nullOr types.path;
          # Prevent key from being copied to store
          apply = mapNullable toString;
          default = null;
          description = ''
            SSH private key file to use to login to the remote system. Can be
            overridden in individual commands.
          '';
        };
  
        commonArgs = mkOption {
          type = types.listOf types.str;
          default = [];
          example = [ "--no-sync-snap" ];
          description = ''
            Arguments to add to every syncoid command, unless disabled for that
            command. See
            <link xlink:href="https://github.com/jimsalterjrs/sanoid/#syncoid-command-line-options"/>
            for available options.
          '';
        };
  
        service = mkOption {
          type = types.attrs;
          default = {};
          description = ''
            Systemd configuration common to all syncoid services.
          '';
        };
  
        commands = mkOption {
          type = types.attrsOf (types.submodule ({ name, ... }: {
            options = {
              source = mkOption {
                type = types.str;
                example = "pool/dataset";
                description = ''
                  Source ZFS dataset. Can be either local or remote. Defaults to
                  the attribute name.
                '';
              };
  
              target = mkOption {
                type = types.str;
                example = "user@server:pool/dataset";
                description = ''
                  Target ZFS dataset. Can be either local
                  (<replaceable>pool/dataset</replaceable>) or remote
                  (<replaceable>user@server:pool/dataset</replaceable>).
                '';
              };
  
              recursive = mkEnableOption ''the transfer of child datasets'';
  
              sshKey = mkOption {
                type = types.nullOr types.path;
                # Prevent key from being copied to store
                apply = mapNullable toString;
                description = ''
                  SSH private key file to use to login to the remote system.
                  Defaults to <option>services.syncoid.sshKey</option> option.
                '';
              };
  
              sendOptions = mkOption {
                type = types.separatedString " ";
                default = "";
                example = "Lc e";
                description = ''
                  Advanced options to pass to zfs send. Options are specified
                  without their leading dashes and separated by spaces.
                '';
              };
  
              recvOptions = mkOption {
                type = types.separatedString " ";
                default = "";
                example = "ux recordsize o compression=lz4";
                description = ''
                  Advanced options to pass to zfs recv. Options are specified
                  without their leading dashes and separated by spaces.
                '';
              };
  
              useCommonArgs = mkOption {
                type = types.bool;
                default = true;
                description = ''
                  Whether to add the configured common arguments to this command.
                '';
              };
  
              service = mkOption {
                type = types.attrs;
                default = {};
                description = ''
                  Systemd configuration specific to this syncoid service.
                '';
              };
  
              extraArgs = mkOption {
                type = types.listOf types.str;
                default = [];
                example = [ "--sshport 2222" ];
                description = "Extra syncoid arguments for this command.";
              };
            };
            config = {
              source = mkDefault name;
              sshKey = mkDefault cfg.sshKey;
            };
          }));
          default = {};
          example = literalExample ''
            {
              "pool/test".target = "root@target:pool/test";
            }
          '';
          description = "Syncoid commands to run.";
        };
      };
  
      # Implementation
  
      config = mkIf cfg.enable {
        users = {
          users = mkIf (cfg.user == "syncoid") {
            syncoid = {
              group = cfg.group;
              isSystemUser = true;
              # For syncoid to be able to create /var/lib/syncoid/.ssh/
              # and to use custom ssh_config or known_hosts.
              home = "/var/lib/syncoid";
              createHome = false;
            };
          };
          groups = mkIf (cfg.group == "syncoid") {
            syncoid = {};
          };
        };
  
        systemd.services = mapAttrs' (name: c:
          nameValuePair "syncoid-${escapeUnitName name}" (mkMerge [
            { description = "Syncoid ZFS synchronization from ${c.source} to ${c.target}";
              after = [ "zfs.target" ];
              startAt = cfg.interval;
              # syncoid may need zpool to get feature@extensible_dataset
  
negative.code:                 ++ optional c.recursive "-r"
                  ++ optionals (c.sshKey != null) [ "--sshkey" c.sshKey ]
                  ++ c.extraArgs
                  ++ [
                  "--sendoptions"
                  c.sendOptions
                  "--recvoptions"
                  c.recvOptions
                  "--no-privilege-elevation"
                  c.source
                  c.target
                ]);
                User = cfg.user;
                Group = cfg.group;
                StateDirectory = [ "syncoid" ];
  