upstream. Specifically, Cinnamon defaults to the gtk2 style instead now,
  following the default in Linux Mint). If you still want Adwaita used, you may
  add the following options to your configuration. Please be aware, that it
  will probably be removed eventually.

  ```nix
  {
    qt = {
      enable = true;
      platformTheme = "gnome";
      style = "adwaita";
    };
  }
  ```

- DocBook option documentation is no longer supported, all module documentation
  now uses Markdown.

- Docker defaults to v24 now, as 20.10 is stopping to receive security updates
  and bug fixes after [December 10,
  2023](https://github.com/moby/moby/discussions/45104).

- Elixir defaults to v1.15 now. Refer to their
  [changelog](https://elixir-lang.org/blog/2023/06/19/elixir-v1-15-0-released/)
  for more details.

- The `extend` function of `llvmPackages` has been removed due it coming from
  the `tools` attrset thus only extending the `tool` attrset. A possible
  replacement is to construct the set from `libraries` and `tools`, or patch
  nixpkgs.

- `ffmpeg` defaults to `ffmpeg_6` now, upgrading from `ffmpeg_5`.

- `fontconfig` defaults to using greyscale antialiasing now. Previously
  subpixel antialiasing was used because of a [recommendation from one of the
  downstreams](https://gitlab.freedesktop.org/fontconfig/fontconfig/-/issues/337).
  You can change this value by configuring
  [](#opt-fonts.fontconfig.subpixel.rgba) accordingly.

- The `fonts.fonts` and `fonts.enableDefaultFonts` options have been renamed to
  `fonts.packages` and `fonts.enableDefaultPackages` respectively.

- `services.hedgedoc` has been heavily refactored, reducing the amount of
  declared options in the module. Most of the options should still work without
  any changes to the configuration. Some options have been deprecated, as they
  no longer have any effect. Refer to [PR
  #244941](https://github.com/NixOS/nixpkgs/pull/244941) for more details.

- `jq` was updated to v1.7. This is its [first release in 5
  years](https://github.com/jqlang/jq/releases/tag/jq-1.7).

- [`lib.attrsets.foldlAttrs`](https://nixos.org/manual/nixpkgs/stable#function-library-lib.attrsets.foldlAttrs)
  now always evaluates the initial accumulator argument first.

- [`lib.lists.foldl'`](https://nixos.org/manual/nixpkgs/stable#function-library-lib.lists.foldl-prime)
  now always evaluates the initial accumulator argument first. If you depend on
  the lazier behavior, consider using
  [`lib.lists.foldl`](https://nixos.org/manual/nixpkgs/stable#function-library-lib.lists.foldl)
  or
  [`builtins.foldl'`](https://nixos.org/manual/nix/stable/language/builtins.html#builtins-foldl')
  instead.

-  Now `magma` defaults to `magma-hip` instead of `magma-cuda`. It also
   respects the `config.cudaSupport` and `config.rocmSupport` options.

- The MariaDB C client library was upgraded from v3.2.x to v3.3.x. Refer to the
  [upstream release
  notes](https://mariadb.com/kb/en/mariadb-connector-c-33-release-notes/) for
  more details.

- Mattermost has been upgraded to extended support version 8.1 as the previously
  packaged extended support version 7.8 is [reaching end-of-life](https://docs.mattermost.com/upgrade/extended-support-release.html).
  Migration may take some time, refer to the [changelog](https://docs.mattermost.com/install/self-managed-changelog.html#release-v8-1-extended-support-release)
  and [important upgrade notes](https://docs.mattermost.com/upgrade/important-upgrade-notes.html).

- The `netdata` package disables cloud support by default now. To enable it use the `netdataCloud` package.

- `networking.nftables` is no longer flushing all rulesets on every reload.
  Use `networking.nftables.flushRuleset = true;` to enable the previous behaviour.

- Node.js v14, v16 has been removed as they were end of life. Any dependent packages that contributors were not able to reasonably upgrade were dropped after a month of notice to their maintainers, were **removed**.
  - This includes VSCode Server.