- The SLIM Display Manager has been removed, as it has been unmaintained since 2013. Consider migrating to a different display manager such as LightDM (current default in NixOS), SDDM, GDM, or using the startx module which uses Xinitrc.
- The Way Cooler wayland compositor has been removed, as the project has been officially canceled. There are no more `way-cooler` attribute and `programs.way-cooler` options.
- The BEAM package set has been deleted. You will only find there the different interpreters. You should now use the different build tools coming with the languages with sandbox mode disabled.
- There is now only one Xfce package-set and module. This means that attributes `xfce4-14` and `xfceUnstable` all now point to the latest Xfce 4.14 packages. And in the future NixOS releases will be the latest released version of Xfce available at the time of the release's development (if viable).
- The [phpfpm](options.html#opt-services.phpfpm.pools) module now sets `PrivateTmp=true` in its systemd units for better process isolation. If you rely on `/tmp` being shared with other services, explicitly override this by setting `serviceConfig.PrivateTmp` to `false` for each phpfpm unit.
- KDE's old multimedia framework Phonon no longer supports Qt 4. For that reason, Plasma desktop also does not have `enableQt4Support` option any more.
- The BeeGFS module has been removed.
- The osquery module has been removed.
- Going forward, `~/bin` in the users home directory will no longer be in `PATH` by default. If you depend on this you should set the option `environment.homeBinInPath` to `true`. The aforementioned option was added this release.
- The `buildRustCrate` infrastructure now produces `lib` outputs in addition to the `out` output. This has led to drastically reduced closure sizes for some rust crates since development dependencies are now in the `lib` output.
- Pango was upgraded to 1.44, which no longer uses freetype for font loading. This means that type1 and bitmap fonts are no longer supported in applications relying on Pango for font rendering (notably, GTK application). See [ upstream issue](https://gitlab.gnome.org/GNOME/pango/issues/386) for more information.
- The `roundcube` module has been hardened.
- The password of the database is not written world readable in the store any more. If `database.host` is set to `localhost`, then a unix user of the same name as the database will be created and PostreSQL peer authentication will be used, removing the need for a password. Otherwise, a password is still needed and can be provided with the new option `database.passwordFile`, which should be set to the path of a file containing the password and readable by the user `nginx` only. The `database.password` option is insecure and deprecated. Usage of this option will print a warning.
- A random `des_key` is set by default in the configuration of roundcube, instead of using the hardcoded and insecure default. To ensure a clean migration, all users will be logged out when you upgrade to this release.
- The packages `openobex` and `obexftp` are no longer installed when enabling Bluetooth via `hardware.bluetooth.enable`.
- The `dump1090` derivation has been changed to use FlightAware's dump1090 as its upstream. However, this version does not have an internal webserver anymore. The assets in the `share/dump1090` directory of the derivation can be used in conjunction with an external webserver to replace this functionality.
- The fourStore and fourStoreEndpoint modules have been removed.
- Polkit no longer has the user of uid 0 (root) as an admin identity. We now follow the upstream default of only having every member of the wheel group admin privileged. Before it was root and members of wheel. The positive outcome of this is pkexec GUI popups or terminal prompts will no longer require the user to choose between two essentially equivalent choices (whether to perform the action as themselves with wheel permissions, or as the root user).