NixOS Release 21.05 Incompatibilities and Changes (Continued)

- If you are using `services.udev.extraRules` to assign custom names to network interfaces, this may stop working due to a change in the initialisation of dhcpcd and systemd networkd. To avoid this, either move them to `services.udev.initrdRules` or see the new [Assigning custom names](#sec-custom-ifnames) section of the NixOS manual for an example using networkd links. - The `security.hideProcessInformation` module has been removed. It was broken since the switch to cgroups-v2. - The `linuxPackages.ati_drivers_x11` kernel modules have been removed. The drivers only supported kernels prior to 4.2, and thus have become obsolete. - The `systemConfig` kernel parameter is no longer added to boot loader entries. It has been unused since September 2010, but if do have a system generation from that era, you will now be unable to boot into them. - `systemd-journal2gelf` no longer parses json and expects the receiving system to handle it. How to achieve this with Graylog is described in this [GitHub issue](https://github.com/parse-nl/SystemdJournal2Gelf/issues/10). - If the `services.dbus` module is enabled, then the user D-Bus session is now always socket activated. The associated options `services.dbus.socketActivated` and `services.xserver.startDbusSession` have therefore been removed and you will receive a warning if they are present in your configuration. This change makes the user D-Bus session available also for non-graphical logins. - The `networking.wireless.iwd` module now installs the upstream-provided 80-iwd.link file, which sets the NamePolicy= for all wlan devices to "keep kernel", to avoid race conditions between iwd and networkd. If you don't want this, you can set `systemd.network.links."80-iwd" = lib.mkForce {}`. - `rubyMinimal` was removed due to being unused and unusable. The default ruby interpreter includes JIT support, which makes it reference it's compiler. Since JIT support is probably needed by some Gems, it was decided to enable this feature with all cc references by default, and allow to build a Ruby derivation without references to cc, by setting `jitSupport = false;` in an overlay. See [\#90151](https://github.com/NixOS/nixpkgs/pull/90151) for more info. - Setting `services.openssh.authorizedKeysFiles` now also affects which keys `security.pam.enableSSHAgentAuth` will use. WARNING: If you are using these options in combination do make sure that any key paths you use are present in `services.openssh.authorizedKeysFiles`! - The option `fonts.enableFontDir` has been renamed to [fonts.fontDir.enable](options.html#opt-fonts.fontDir.enable). The path of font directory has also been changed to `/run/current-system/sw/share/X11/fonts`, for consistency with other X11 resources. - A number of options have been renamed in the kicad interface. `oceSupport` has been renamed to `withOCE`, `withOCCT` has been renamed to `withOCC`, `ngspiceSupport` has been renamed to `withNgspice`, and `scriptingSupport` has been renamed to `withScripting`. Additionally, `kicad/base.nix` no longer provides default argument values since these are provided by `kicad/default.nix`. - The socket for the `pdns-recursor` module was moved from `/var/lib/pdns-recursor` to `/run/pdns-recursor` to match upstream. - Paperwork was updated to version 2. The on-disk format slightly changed, and it is not possible to downgrade from Paperwork 2 back to Paperwork 1.3. Back your documents up before upgrading. See [this thread](https://forum.openpaper.work/t/paperwork-2-0/112/5) for more details. - PowerDNS has been updated from `4.2.x` to `4.3.x`. Please be sure to review the [Upgrade Notes](https://doc.powerdns.com/authoritative/upgrading.html#x-to-4-3-0) provided by upstream before upgrading. Worth specifically noting is that the service now runs entirely as a dedicated `pdns` user, instead of starting as `root` and dropping privileges, as well as the default `socket-dir` location changing from `/var/lib/powerdns` to `/run/pdns`. - The `mediatomb` service is now using by default the new and maintained fork `gerbera` package instead of the unmaintained `mediatomb` package. If you want to keep the old behavior, you must declare it with:

This section details further backward incompatibilities and changes in NixOS Release 21.05, including modifications to network interface naming, removal of the `security.hideProcessInformation` module, obsolete ATI drivers, the removal of the `systemConfig` kernel parameter, changes to `systemd-journal2gelf`, socket activation for user D-Bus sessions, default settings for iwd, removal of `rubyMinimal`, impact of `services.openssh.authorizedKeysFiles` on SSH agent authentication, renaming of `fonts.enableFontDir`, renamed options in the KiCad interface, relocation of the `pdns-recursor` socket, updates to Paperwork, PowerDNS updates and changes in user and socket directory, and the switch from `mediatomb` to `gerbera`.