# Release 24.05 (“Uakari”, 2024.05/??) {#sec-release-24.05}

Support is planned until the end of December 2024, handing over to 24.11.

## Highlights {#sec-release-24.05-highlights}

In addition to numerous new and upgraded packages, this release has the following highlights:

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- `cryptsetup` has been upgraded from 2.6.1 to 2.7.0. Cryptsetup is a critical component enabling LUKS-based (but not only) full disk encryption.
  Take the time to review [the release notes](https://gitlab.com/cryptsetup/cryptsetup/-/raw/v2.7.0/docs/v2.7.0-ReleaseNotes).
  One of the highlight is that it is now possible to use hardware OPAL-based encryption of your disk with `cryptsetup`, it has a lot of caveats, see the above notes for the full details.

- `screen`'s module has been cleaned, and will now require you to set `programs.screen.enable` in order to populate `screenrc` and add the program to the environment.

- `linuxPackages_testing_bcachefs` is now fully deprecated by `linuxPackages_latest`, and is therefore no longer available.

- The default kernel package has been updated from 6.1 to 6.6. All supported kernels remain available.

- NixOS now installs a stub ELF loader that prints an informative error message when users attempt to run binaries not made for NixOS.
   - This can be disabled through the `environment.stub-ld.enable` option.
   - If you use `programs.nix-ld.enable`, no changes are needed. The stub will be disabled automatically.

- On flake-based NixOS configurations using `nixpkgs.lib.nixosSystem`, NixOS will automatically set `NIX_PATH` and the system-wide flake registry (`/etc/nix/registry.json`) to point `<nixpkgs>` and the unqualified flake path `nixpkgs` to the version of nixpkgs used to build the system.

  This makes `nix run nixpkgs#hello` and `nix-build '<nixpkgs>' -A hello` work out of the box with no added configuration, reusing dependencies already on the system.

  This may be undesirable if nix commands are not going to be run on the built system since it adds nixpkgs to the system closure. For such closure-size-constrained non-interactive systems, this setting should be disabled.

  To disable this, set [nixpkgs.flake.setNixPath](#opt-nixpkgs.flake.setNixPath) and [nixpkgs.flake.setFlakeRegistry](#opt-nixpkgs.flake.setFlakeRegistry) to false.

- Julia environments can now be built with arbitrary packages from the ecosystem using the `.withPackages` function. For example: `julia.withPackages ["Plots"]`.

- A new option `systemd.sysusers.enable` was added. If enabled, users and
  groups are created with systemd-sysusers instead of with a custom perl script.

- A new option `virtualisation.containers.cdi` was added. It contains `static` and `dynamic` attributes (corresponding to `/etc/cdi` and `/run/cdi` respectively) to configure the Container Device Interface (CDI).

- `virtualisation.docker.enableNvidia` and `virtualisation.podman.enableNvidia` options are deprecated. `virtualisation.containers.cdi.dynamic.nvidia.enable` should be used instead. This option will expose GPUs on containers with the `--device` CLI option. This is supported by Docker 25, Podman 3.2.0 and Singularity 4. Any container runtime that supports the CDI specification will take advantage of this feature.

- A new option `system.etc.overlay.enable` was added. If enabled, `/etc` is
  mounted via an overlayfs instead of being created by a custom perl script.

- It is now possible to have a completely perlless system (i.e. a system
  without perl). Previously, the NixOS activation depended on two perl scripts
  which can now be replaced via an opt-in mechanism. To make your system
  perlless, you can use the new perlless profile:
  ```
  { modulesPath, ... }: {
    imports = [ "${modulesPath}/profiles/perlless.nix" ];
  }
  ```

- Plasma 6 is now available and can be installed with `services.xserver.desktopManager.plasma6.enable = true;`. Plasma 5 will likely be deprecated in the next release (24.11). Note that Plasma 6 runs as Wayland by default, and the X11 session needs to be explicitly selected if necessary.

## New Services {#sec-release-24.05-new-services}

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- [Handheld Daemon](https://github.com/hhd-dev/hhd), support for gaming handhelds like the Legion Go, ROG Ally, and GPD Win. Available as [services.handheld-daemon](#opt-services.handheld-daemon.enable).

- [Guix](https://guix.gnu.org), a functional package manager inspired by Nix. Available as [services.guix](#opt-services.guix.enable).

- [pyLoad](https://pyload.net/), a FOSS download manager written in Python. Available as [services.pyload](#opt-services.pyload.enable)

- [maubot](https://github.com/maubot/maubot), a plugin-based Matrix bot framework. Available as [services.maubot](#opt-services.maubot.enable).

- systemd's gateway, upload, and remote services, which provides ways of sending journals across the network. Enable using [services.journald.gateway](#opt-services.journald.gateway.enable), [services.journald.upload](#opt-services.journald.upload.enable), and [services.journald.remote](#opt-services.journald.remote.enable).

- [GNS3](https://www.gns3.com/), a network software emulator. Available as [services.gns3-server](#opt-services.gns3-server.enable).

- [pretalx](https://github.com/pretalx/pretalx), a conference planning tool. Available as [services.pretalx](#opt-services.pretalx.enable).

- [rspamd-trainer](https://gitlab.com/onlime/rspamd-trainer), script triggered by a helper which reads mails from a specific mail inbox and feeds them into rspamd for spam/ham training.

- [ollama](https://ollama.ai), server for running large language models locally.

- [hebbot](https://github.com/haecker-felix/hebbot), a Matrix bot to generate "This Week in X" like blog posts. Available as [services.hebbot](#opt-services.hebbot.enable).

- [Anki Sync Server](https://docs.ankiweb.net/sync-server.html), the official sync server built into recent versions of Anki. Available as [services.anki-sync-server](#opt-services.anki-sync-server.enable).
The pre-existing [services.ankisyncd](#opt-services.ankisyncd.enable) has been marked deprecated and will be dropped after 24.05 due to lack of maintenance of the anki-sync-server softwares.

- [Suwayomi Server](https://github.com/Suwayomi/Suwayomi-Server), a free and open source manga reader server that runs extensions built for [Tachiyomi](https://tachiyomi.org). Available as [services.suwayomi-server](#opt-services.suwayomi-server.enable).

- [ping_exporter](https://github.com/czerwonk/ping_exporter), a Prometheus exporter for ICMP echo requests. Available as [services.prometheus.exporters.ping](#opt-services.prometheus.exporters.ping.enable).

- [TigerBeetle](https://tigerbeetle.com/), a distributed financial accounting database designed for mission critical safety and performance. Available as [services.tigerbeetle](#opt-services.tigerbeetle.enable).

- [go-camo](https://github.com/cactus/go-camo), a secure image proxy server. Available as [services.go-camo](#opt-services.go-camo.enable).

- [Monado](https://monado.freedesktop.org/), an open source XR runtime. Available as [services.monado](#opt-services.monado.enable).

- [Clevis](https://github.com/latchset/clevis), a pluggable framework for automated decryption, used to unlock encrypted devices in initrd. Available as [boot.initrd.clevis.enable](#opt-boot.initrd.clevis.enable).

- [armagetronad](https://wiki.armagetronad.org), a mid-2000s 3D lightcycle game widely played at iD Tech Camps. You can define multiple servers using `services.armagetronad.<server>.enable`.

- [TuxClocker](https://github.com/Lurkki14/tuxclocker), a hardware control and monitoring program. Available as [programs.tuxclocker](#opt-programs.tuxclocker.enable).

- [ALVR](https://github.com/alvr-org/alvr), a VR desktop streamer. Available as [programs.alvr](#opt-programs.alvr.enable)

- [RustDesk](https://rustdesk.com), a full-featured open source remote control alternative for self-hosting and security with minimal configuration. Alternative to TeamViewer.

- [Scrutiny](https://github.com/AnalogJ/scrutiny), a S.M.A.R.T monitoring tool for hard disks with a web frontend.

- [systemd-lock-handler](https://git.sr.ht/~whynothugo/systemd-lock-handler/), a bridge between logind D-Bus events and systemd targets. Available as [services.systemd-lock-handler.enable](#opt-services.systemd-lock-handler.enable).

- [Mealie](https://nightly.mealie.io/), a self-hosted recipe manager and meal planner with a RestAPI backend and a reactive frontend application built in NuxtJS for a pleasant user experience for the whole family. Available as [services.mealie](#opt-services.mealie.enable)

## Backward Incompatibilities {#sec-release-24.05-incompatibilities}

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- `himalaya` was updated to `v1.0.0-beta.3`, which introduces breaking changes. Check out the [release note](https://github.com/soywod/himalaya/releases/tag/v1.0.0-beta.3) for details.

- The `power.ups` module now generates `upsd.conf`, `upsd.users` and `upsmon.conf` automatically from a set of new configuration options. This breaks compatibility with existing `power.ups` setups where these files were created manually. Back up these files before upgrading NixOS.

- `k9s` was updated to v0.31. There have been various breaking changes in the config file format,
  check out the changelog of [v0.29](https://github.com/derailed/k9s/releases/tag/v0.29.0),
  [v0.30](https://github.com/derailed/k9s/releases/tag/v0.30.0) and
  [v0.31](https://github.com/derailed/k9s/releases/tag/v0.31.0) for details. It is recommended
  to back up your current configuration and let k9s recreate the new base configuration.

- `idris2` was updated to v0.7.0. This version introduces breaking changes. Check out the [changelog](https://github.com/idris-lang/Idris2/blob/v0.7.0/CHANGELOG.md#v070) for details.

- `neo4j` has been updated to 5, you may want to read the [release notes for Neo4j 5](https://neo4j.com/release-notes/database/neo4j-5/)

- `services.neo4j.allowUpgrade` was removed and no longer has any effect. Neo4j 5 supports automatic rolling upgrades.

- `nitter` requires a `guest_accounts.jsonl` to be provided as a path or loaded into the default location at `/var/lib/nitter/guest_accounts.jsonl`. See [Guest Account Branch Deployment](https://github.com/zedeus/nitter/wiki/Guest-Account-Branch-Deployment) for details.

- `boot.supportedFilesystems` and `boot.initrd.supportedFilesystems` are now attribute sets instead of lists. Assignment from lists as done previously is still supported, but checking whether a filesystem is enabled must now by done using `supportedFilesystems.fs or false` instead of using `lib.elem "fs" supportedFilesystems` as was done previously.

- `services.aria2.rpcSecret` has been replaced with `services.aria2.rpcSecretFile`.
  This was done so that secrets aren't stored in the world-readable nix store.
  To migrate, you will have create a file with the same exact string, and change
  your module options to point to that file. For example, `services.aria2.rpcSecret =
  "mysecret"` becomes `services.aria2.rpcSecretFile = "/path/to/secret_file"`
  where the file `secret_file` contains the string `mysecret`.

- Invidious has changed its default database username from `kemal` to `invidious`. Setups involving an externally provisioned database (i.e. `services.invidious.database.createLocally == false`) should adjust their configuration accordingly. The old `kemal` user will not be removed automatically even when the database is provisioned automatically.(https://github.com/NixOS/nixpkgs/pull/265857)

- `inetutils` now has a lower priority to avoid shadowing the commonly used `util-linux`. If one wishes to restore the default priority, simply use `lib.setPrio 5 inetutils` or override with `meta.priority = 5`.

- `paperless`' `services.paperless.extraConfig` setting has been removed and converted to the freeform type and option named `services.paperless.settings`.

- The legacy and long deprecated systemd target `network-interfaces.target` has been removed. Use `network.target` instead.

- `services.frp.settings` now generates the frp configuration file in TOML format as [recommended by upstream](https://github.com/fatedier/frp#configuration-files), instead of the legacy INI format. This has also introduced other changes in the configuration file structure and options.
  - The `settings.common` section in the configuration is no longer valid and all the options form inside it now goes directly under `settings`.
  - The `_` separating words in the configuration options is removed so the options are now in camel case. For example: `server_addr` becomes `serverAddr`, `server_port` becomes `serverPort` etc.
  - Proxies are now defined with a new option `settings.proxies` which takes a list of proxies.
  - Consult the [upstream documentation](https://github.com/fatedier/frp#example-usage) for more details on the changes.

- `mkosi` was updated to v20. Parts of the user interface have changed. Consult the
  release notes of [v19](https://github.com/systemd/mkosi/releases/tag/v19) and
  [v20](https://github.com/systemd/mkosi/releases/tag/v20) for a list of changes.

- The `woodpecker-*` packages have been updated to v2 which includes [breaking changes](https://woodpecker-ci.org/docs/next/migrations#200).

- `services.nginx` will no longer advertise HTTP/3 availability automatically. This must now be manually added, preferably to each location block.
  Example:

  ```nix
    locations."/".extraConfig = ''
      add_header Alt-Svc 'h3=":$server_port"; ma=86400';
    '';
    locations."^~ /assets/".extraConfig = ''
      add_header Alt-Svc 'h3=":$server_port"; ma=86400';
    '';

  ```

- The package `optparse-bash` is now dropped due to upstream inactivity. Alternatives available in Nixpkgs include [`argc`](https://github.com/sigoden/argc), [`argbash`](https://github.com/matejak/argbash), [`bashly`](https://github.com/DannyBen/bashly) and [`gum`](https://github.com/charmbracelet/gum), to name a few.

- The `kanata` package has been updated to v1.5.0, which includes [breaking changes](https://github.com/jtroo/kanata/releases/tag/v1.5.0).

- The `craftos-pc` package has been updated to v2.8, which includes [breaking changes](https://github.com/MCJack123/craftos2/releases/tag/v2.8).
  - Files are now handled in binary mode; this could break programs with embedded UTF-8 characters.
  - The ROM was updated to match ComputerCraft version v1.109.2.
  - The bundled Lua was updated to Lua v5.2, which includes breaking changes. See the [Lua manual](https://www.lua.org/manual/5.2/manual.html#8) for more information.
  - The WebSocket API [was rewritten](https://github.com/MCJack123/craftos2/issues/337), which introduced breaking changes.

- The `gtest` package has been updated past v1.13.0, which requires C++14 or higher.

- The latest available version of Nextcloud is v28 (available as `pkgs.nextcloud28`). The installation logic is as follows:
  - If [`services.nextcloud.package`](#opt-services.nextcloud.package) is specified explicitly, this package will be installed (**recommended**)
  - If [`system.stateVersion`](#opt-system.stateVersion) is >=24.05, `pkgs.nextcloud28` will be installed by default.
  - If [`system.stateVersion`](#opt-system.stateVersion) is >=23.11, `pkgs.nextcloud27` will be installed by default.
  - Please note that an upgrade from v26 (or older) to v28 directly is not possible. Please upgrade to `nextcloud27` (or earlier) first. Nextcloud prohibits skipping major versions while upgrading. You can upgrade by declaring [`services.nextcloud.package = pkgs.nextcloud27;`](options.html#opt-services.nextcloud.package).

- The vendored third party libraries have been mostly removed from `cudaPackages.nsight_systems`, which we now only ship for `cudaPackages_11_8` and later due to outdated dependencies. Users comfortable with the vendored dependencies may use `overrideAttrs` to amend the `postPatch` phase and the `meta.broken` correspondingly. Alternatively, one could package the deprecated `boost170` locally, as required for `cudaPackages_11_4.nsight_systems`.

- The `cudaPackages` package scope has been updated to `cudaPackages_12`.

- Ada packages (libraries and tools) have been moved into the `gnatPackages` scope. `gnatPackages` uses the default GNAT compiler, `gnat12Packages` and `gnat13Packages` use the respective matching compiler version.

- `spark2014` has been renamed to `gnatprove`. A version of `gnatprove` matching different GNAT versions is available from the different `gnatPackages` sets.

- `services.resolved.fallbackDns` can now be used to disable the upstream fallback servers entirely by setting it to an empty list. To get the previous behaviour of the upstream defaults set it to null, the new default, instead.

- `xxd` has been moved from `vim` default output to its own output to reduce closure size. The canonical way to reference it across all platforms is `unixtools.xxd`.

- The `stalwart-mail` package has been updated to v0.5.3, which includes [breaking changes](https://github.com/stalwartlabs/mail-server/blob/v0.5.3/UPGRADING.md).

- `services.zope2` has been removed as `zope2` is unmaintained and was relying on Python2.

- `services.avahi.nssmdns` got split into `services.avahi.nssmdns4` and `services.avahi.nssmdns6` which enable the mDNS NSS switch for IPv4 and IPv6 respectively.
  Since most mDNS responders only register IPv4 addresses, most users want to keep the IPv6 support disabled to avoid long timeouts.

- A warning has been added for services that are
  `after = [ "network-online.target" ]` but do not depend on it (e.g. using
  `wants`), because the dependency that `multi-user.target` has on
  `network-online.target` is planned for removal.

- `services.pgbouncer` now has systemd support enabled and will log to journald. The default setting for `services.pgbouncer.logFile` is now `null` to disable logging to a separate log file.

- `services.archisteamfarm` no longer uses the abbreviation `asf` for its state directory (`/var/lib/asf`), user and group (both `asf`). Instead the long name `archisteamfarm` is used.
  Configurations with `system.stateVersion` 23.11 or earlier, default to the old stateDirectory until the 24.11 release and must either set the option explicitly or move the data to the new directory.

- `networking.iproute2.enable` now does not set `environment.etc."iproute2/rt_tables".text`.

  Setting `environment.etc."iproute2/{CONFIG_FILE_NAME}".text` will override the whole configuration file instead of appending it to the upstream configuration file.

  `CONFIG_FILE_NAME` includes `bpf_pinning`, `ematch_map`, `group`, `nl_protos`, `rt_dsfield`, `rt_protos`, `rt_realms`, `rt_scopes`, and `rt_tables`.

- `netbox` was updated to v3.7. `services.netbox.package` still defaults
  to v3.6 if `stateVersion` is earlier than 24.05. Refer to upstream's breaking
  changes [for
  v3.7.0](https://github.com/netbox-community/netbox/releases/tag/v3.7.0) and
  upgrade NetBox by changing `services.netbox.package`. Database migrations
  will be run automatically.

- The executable file names for `firefox-devedition`, `firefox-beta`, `firefox-esr` now matches their package names, which is consistent with the `firefox-*-bin` packages. The desktop entries are also updated so that you can have multiple editions of firefox in your app launcher.

- switch-to-configuration does not directly call systemd-tmpfiles anymore.
  Instead, the new artificial sysinit-reactivation.target is introduced which
  allows to restart multiple services that are ordered before sysinit.target
  and respect the ordering between the services.

- The `systemd.oomd` module behavior is changed as:

  - Raise ManagedOOMMemoryPressureLimit from 50% to 80%. This should make systemd-oomd kill things less often, and fix issues like [this](https://pagure.io/fedora-workstation/issue/358).
    Reference: [commit](https://src.fedoraproject.org/rpms/systemd/c/806c95e1c70af18f81d499b24cd7acfa4c36ffd6?branch=806c95e1c70af18f81d499b24cd7acfa4c36ffd6)

  - Remove swap policy. This helps prevent killing processes when user's swap is small.

  - Expand the memory pressure policy to system.slice, user-.slice, and all user owned slices. Reference: [commit](https://src.fedoraproject.org/rpms/systemd/c/7665e1796f915dedbf8e014f0a78f4f576d609bb)

  - `systemd.oomd.enableUserServices` is renamed to `systemd.oomd.enableUserSlices`.

- `security.pam.enableSSHAgentAuth` now requires `services.openssh.authorizedKeysFiles` to be non-empty,
  which is the case when `services.openssh.enable` is true. Previously, `pam_ssh_agent_auth` silently failed to work.

- The configuration format for `services.prometheus.exporters.snmp` changed with release 0.23.0.
  The module now includes an optional config check, that is enabled by default, to make the change obvious before any deployment.
  More information about the configuration syntax change is available in the [upstream repository](https://github.com/prometheus/snmp_exporter/blob/b75fc6b839ee3f3ccbee68bee55f1ae99555084a/auth-split-migration.md).

- [watchdogd](https://troglobit.com/projects/watchdogd/), a system and process supervisor using watchdog timers. Available as [services.watchdogd](#opt-services.watchdogd.enable).

- The `jdt-language-server` package now uses upstream's provided python wrapper instead of our own custom wrapper. This results in the following breaking and notable changes:

  - The main binary for the package is now named `jdtls` instead of `jdt-language-server`, equivalent to what most editors expect the binary to be named.

  - JVM arguments should now be provided with the `--jvm-arg` flag instead of setting `JAVA_OPTS`.

  - The `-data` path is no longer required to run the package, and will be set to point to a folder in `$TMP` if missing.

- `nomad` has been updated - note that HashiCorp recommends updating one minor version at a time. Please check [their upgrade guide](https://developer.hashicorp.com/nomad/docs/upgrade) for information on safely updating clusters and potential breaking changes.

  - `nomad` is now Nomad 1.7.x.

  - `nomad_1_4` has been removed, as it is now unsupported upstream.

- The `livebook` package is now built as a `mix release` instead of an `escript`.
  This means that configuration now has to be done using [environment variables](https://hexdocs.pm/livebook/readme.html#environment-variables) instead of command line arguments.
  This has the further implication that the `livebook` service configuration has changed:

  - The `erlang_node_short_name`, `erlang_node_name`, `port` and `options` configuration parameters are gone, and have been replaced with an `environment` parameter.
    Use the appropriate [environment variables](https://hexdocs.pm/livebook/readme.html#environment-variables) inside `environment` to configure the service instead.

## Other Notable Changes {#sec-release-24.05-notable-changes}

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- `addDriverRunpath` has been added to facilitate the deprecation of the old `addOpenGLRunpath` setuphook. This change is motivated by the evolution of the setuphook to include all hardware acceleration.

- Cinnamon has been updated to 6.0. Please beware that the [Wayland session](https://blog.linuxmint.com/?p=4591) is still experimental in this release.

- New `boot.loader.systemd-boot.xbootldrMountPoint` allows setting up a separate [XBOOTLDR partition](https://uapi-group.org/specifications/specs/boot_loader_specification/) to store boot files. Useful on systems with a small EFI System partition that cannot be easily repartitioned.

- `boot.loader.systemd-boot` will now verify that `efiSysMountPoint` (and `xbootldrMountPoint` if configured) are mounted partitions.

- `services.postgresql.extraPlugins` changed its type from just a list of packages to also a function that returns such a list.
  For example a config line like ``services.postgresql.extraPlugins = with pkgs.postgresql_11.pkgs; [ postgis ];`` is recommended to be changed to ``services.postgresql.extraPlugins = ps: with ps; [ postgis ];``;

- The Matrix homeserver [Synapse](https://element-hq.github.io/synapse/) module now supports configuring UNIX domain socket [listeners](#opt-services.matrix-synapse.settings.listeners) through the `path` option.
  The default replication worker on the main instance has been migrated away from TCP sockets to UNIX domain sockets.

- Programs written in [Nim](https://nim-lang.org/) are built with libraries selected by lockfiles.
  The `nimPackages` and `nim2Packages` sets have been removed.
  See https://nixos.org/manual/nixpkgs/unstable#nim for more information.

- [Portunus](https://github.com/majewsky/portunus) has been updated to major version 2.
  This version of Portunus supports strong password hashes, but the legacy hash SHA-256 is also still supported to ensure a smooth migration of existing user accounts.
  After upgrading, follow the instructions on the [upstream release notes](https://github.com/majewsky/portunus/releases/tag/v2.0.0) to upgrade all user accounts to strong password hashes.
  Support for weak password hashes will be removed in NixOS 24.11.

- A stdenv's default set of hardening flags can now be set via its `bintools-wrapper`'s `defaultHardeningFlags` argument. A convenient stdenv adapter, `withDefaultHardeningFlags`, can be used to override an existing stdenv's `defaultHardeningFlags`.

- `libass` now uses the native CoreText backend on Darwin, which may fix subtitle rendering issues with `mpv`, `ffmpeg`, etc.

- [Lilypond](https://lilypond.org/index.html) and [Denemo](https://www.denemo.org) are now compiled with Guile 3.0.

- The following options of the Nextcloud module were moved into [`services.nextcloud.settings`](#opt-services.nextcloud.settings) and renamed to match the name from Nextcloud's `config.php`:
  - `logLevel` -> [`loglevel`](#opt-services.nextcloud.settings.loglevel),
  - `logType` -> [`log_type`](#opt-services.nextcloud.settings.log_type),
  - `defaultPhoneRegion` -> [`default_phone_region`](#opt-services.nextcloud.settings.default_phone_region),
  - `overwriteProtocol` -> [`overwriteprotocol`](#opt-services.nextcloud.settings.overwriteprotocol),
  - `skeletonDirectory` -> [`skeletondirectory`](#opt-services.nextcloud.settings.skeletondirectory),
  - `globalProfiles` -> [`profile.enabled`](#opt-services.nextcloud.settings._profile.enabled_),
  - `extraTrustedDomains` -> [`trusted_domains`](#opt-services.nextcloud.settings.trusted_domains) and
  - `trustedProxies` -> [`trusted_proxies`](#opt-services.nextcloud.settings.trusted_proxies).

- The option [`services.nextcloud.config.dbport`] of the Nextcloud module was removed to match upstream.
  The port can be specified in [`services.nextcloud.config.dbhost`](#opt-services.nextcloud.config.dbhost).

- A new abstraction to create both read-only as well as writable overlay file
  systems was added. Available via
  [fileSystems.overlay](#opt-fileSystems._name_.overlay.lowerdir). See also the
  [NixOS docs](#sec-overlayfs).

- systemd units can now specify the `Upholds=` and `UpheldBy=` unit dependencies via the aptly
  named `upholds` and `upheldBy` options. These options get systemd to enforce that the
  dependencies remain continuosly running for as long as the dependent unit is in a running state.

- `stdenv`: The `--replace` flag in `substitute`, `substituteInPlace`, `substituteAll`, `substituteAllStream`, and `substituteStream` is now deprecated if favor of the new `--replace-fail`, `--replace-warn` and `--replace-quiet`. The deprecated `--replace` equates to `--replace-warn`.

- A new hardening flag, `zerocallusedregs` was made available, corresponding to the gcc/clang option `-fzero-call-used-regs=used-gpr`.

- New options were added to the dnsdist module to enable and configure a DNSCrypt endpoint (see `services.dnsdist.dnscrypt.enable`, etc.).
  The module can generate the DNSCrypt provider key pair, certificates and also performs their rotation automatically with no downtime.

- With a bump to `sonarr` v4, existing config database files will be upgraded automatically, but note that some old apparently-working configs [might actually be corrupt and fail to upgrade cleanly](https://forums.sonarr.tv/t/sonarr-v4-released/33089).

- The Yama LSM is now enabled by default in the kernel, which prevents ptracing
  non-child processes. This means you will not be able to attach gdb to an
  existing process, but will need to start that process from gdb (so it is a
  child). Or you can set `boot.kernel.sysctl."kernel.yama.ptrace_scope"` to 0.

- The netbird module now allows running multiple tunnels in parallel through [`services.netbird.tunnels`](#opt-services.netbird.tunnels).

- [Nginx virtual hosts](#opt-services.nginx.virtualHosts) using `forceSSL` or
  `globalRedirect` can now have redirect codes other than 301 through
  `redirectCode`.

- `libjxl` 0.9.0 [dropped support for the butteraugli API](https://github.com/libjxl/libjxl/pull/2576). You will no longer be able to set `enableButteraugli` on `libaom`.

- The source of the `mockgen` package has changed to the [go.uber.org/mock](https://github.com/uber-go/mock) fork because [the original repository is no longer maintained](https://github.com/golang/mock#gomock).

- `security.pam.enableSSHAgentAuth` was renamed to `security.pam.sshAgentAuth.enable` and an `authorizedKeysFiles`
  option was added, to control which `authorized_keys` files are trusted.  It defaults to the previous behaviour,
  **which is insecure**: see [#31611](https://github.com/NixOS/nixpkgs/issues/31611).

- [](#opt-boot.kernel.sysctl._net.core.wmem_max_) changed from a string to an integer because of the addition of a custom merge option (taking the highest value defined to avoid conflicts between 2 services trying to set that value), just as [](#opt-boot.kernel.sysctl._net.core.rmem_max_) since 22.11.

- A new top-level package set, `pkgsExtraHardening` is added. This is a set of packages built with stricter hardening flags - those that have not yet received enough testing to be applied universally, those that are more likely to cause build failures or those that have drawbacks to their use (e.g. performance or required hardware features).

- `services.zfs.zed.enableMail` now uses the global `sendmail` wrapper defined by an email module
  (such as msmtp or Postfix). It no longer requires using a special ZFS build with email support.

- `nextcloud-setup.service` no longer changes the group of each file & directory inside `/var/lib/nextcloud/{config,data,store-apps}` if one of these directories has the wrong owner group. This was part of transitioning the group used for `/var/lib/nextcloud`, but isn't necessary anymore.

- The `krb5` module has been rewritten and moved to `security.krb5`, moving all options but `security.krb5.enable` and `security.krb5.package` into `security.krb5.settings`.

- Gitea 1.21 upgrade has several breaking changes, including:
  - Custom themes and other assets that were previously stored in `custom/public/*` now belong in `custom/public/assets/*`
  - New instances of Gitea using MySQL now ignore the `[database].CHARSET` config option and always use the `utf8mb4` charset, existing instances should migrate via the `gitea doctor convert` CLI command.

- The `services.paperless` module no longer uses the previously downloaded NLTK data stored in `/var/cache/paperless/nltk`. This directory can be removed.

- The `services.teeworlds` module now has a wealth of configuration options, including a new `package` option.

- The `hardware.pulseaudio` module now sets permission of pulse user home directory to 755 when running in "systemWide" mode. It fixes [issue 114399](https://github.com/NixOS/nixpkgs/issues/114399).

- The module `services.github-runner` has been removed. To configure a single GitHub Actions Runner refer to `services.github-runners.*`. Note that this will trigger a new runner registration.

- The `btrbk` module now automatically selects and provides required compression
  program depending on the configured `stream_compress` option. Since this
  replaces the need for the `extraPackages` option, this option will be
  deprecated in future releases.

- The `mpich` package expression now requires `withPm` to be a list, e.g. `"hydra:gforker"` becomes `[ "hydra" "gforker" ]`.

- When merging systemd unit options (of type `unitOption`),
  if at least one definition is a list, all those which aren't are now lifted into a list,
  making it possible to accumulate definitions without resorting to `mkForce`,
  hence to retain the definitions not anticipating that need.

- YouTrack is bumped to 2023.3. The update is not performed automatically, it requires manual interaction. See the YouTrack section in the manual for details.

- QtMultimedia has changed its default backend to `QT_MEDIA_BACKEND=ffmpeg` (previously `gstreamer` on Linux or `darwin` on MacOS).
  The previous native backends remain available but are now minimally maintained. Refer to [upstream documentation](https://doc.qt.io/qt-6/qtmultimedia-index.html#ffmpeg-as-the-default-backend) for further details about each platform.

- The oil shell is now using the c++ version by default. The python based build is still available as `oil-python`
