- `programs.ibus` moved to `i18n.inputMethod.ibus`. The option `programs.ibus.plugins` changed to `i18n.inputMethod.ibus.engines` and the option to enable ibus changed from `programs.ibus.enable` to `i18n.inputMethod.enabled`. `i18n.inputMethod.enabled` should be set to the used input method name, `"ibus"` for ibus. An example of the new style:

  ```nix
  {
    i18n.inputMethod.enabled = "ibus";
    i18n.inputMethod.ibus.engines = with pkgs.ibus-engines; [ anthy mozc ];
  }
  ```

  That is equivalent to the old version:

  ```nix
  {
    programs.ibus.enable = true;
    programs.ibus.plugins = with pkgs; [ ibus-anthy mozc ];
  }
  ```

- `services.udev.extraRules` option now writes rules to `99-local.rules` instead of `10-local.rules`. This makes all the user rules apply after others, so their results wouldn't be overridden by anything else.

- Large parts of the `services.gitlab` module has been been rewritten. There are new configuration options available. The `stateDir` option was renamned to `statePath` and the `satellitesDir` option was removed. Please review the currently available options.

- The option `services.nsd.zones.<name>.data` no longer interpret the dollar sign (\$) as a shell variable, as such it should not be escaped anymore. Thus the following zone data:

  ```dns-zone
  $ORIGIN example.com.
  $TTL 1800
  @       IN      SOA     ns1.vpn.nbp.name.      admin.example.com. (

  ```

  Should modified to look like the actual file expected by nsd:

  ```dns-zone
  $ORIGIN example.com.
  $TTL 1800
  @       IN      SOA     ns1.vpn.nbp.name.      admin.example.com. (

  ```

- `service.syncthing.dataDir` options now has to point to exact folder where syncthing is writing to. Example configuration should look something like:

  ```nix
  {
    services.syncthing = {
        enable = true;
        dataDir = "/home/somebody/.syncthing";
        user = "somebody";
    };
  }
  ```

- `networking.firewall.allowPing` is now enabled by default. Users are encouraged to configure an appropriate rate limit for their machines using the Kernel interface at `/proc/sys/net/ipv4/icmp_ratelimit` and `/proc/sys/net/ipv6/icmp/ratelimit` or using the firewall itself, i.e. by setting the NixOS option `networking.firewall.pingLimit`.