Merge staging-nixos into staging-next

  "module-services-mailman-other-mtas": [

    "index.html#module-services-mailman-other-mtas"

  ],

  "test-opt-requiredFeatures": [

    "index.html#test-opt-requiredFeatures"

  ],

  "test-opt-requiredFeatures.apple-virt": [

    "index.html#test-opt-requiredFeatures.apple-virt"

  ],

  "test-opt-requiredFeatures.devnet": [

    "index.html#test-opt-requiredFeatures.devnet"

  ],

  "test-opt-requiredFeatures.kvm": [

    "index.html#test-opt-requiredFeatures.kvm"

  ],

  "test-opt-requiredFeatures.nixos-test": [

    "index.html#test-opt-requiredFeatures.nixos-test"

  ],

  "test-opt-requiredFeatures.uid-range": [

    "index.html#test-opt-requiredFeatures.uid-range"

  ],

  "trezor": [

    "index.html#trezor"

  ],

- The default kernel package has been updated from 6.12 to 6.18. All supported kernels remain available.

- The default D-Bus implementation has been switched from `dbus` to `dbus-broker`. dbus-broker provides

  higher performance and reliability while maintaining compatibility with the D-Bus reference implementation.

  Note that changing `services.dbus.implementation` is a **switch inhibitor**: switching between

  implementations requires a reboot rather than just `nixos-rebuild switch`, because restarting D-Bus

  mid-session is unsafe.

  Users who wish to keep the classic daemon can set: `services.dbus.implementation = "dbus";`

## New Modules {#sec-release-26.05-new-modules}

<!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

  hostPkgs,

  lib,

  containers,

  nodes,

  options,

  ...

}:

    */

    f:

    lib.mkOverride (opt.highestPrio - 1) (f opt.value);

  requiredFeaturesModuleType = {

    freeformType = types.attrsOf types.bool;

    options = {

      devnet = mkOption {

        type = types.bool;

        default =

          builtins.length (lib.attrNames containers) > 0 && builtins.length (lib.attrNames nodes) > 0;

        defaultText = lib.literalMD "`true` if both VMs and containers are present.";

        description = ''

          This heuristic setting that assumes that the majority of tests requires VMs and containers

          to communicate over network. To support such tests, adding "/dev/net" to `nix.settings.extra-sandbox-paths` is necessary.

          Override this to `false` if the heuristic is wrong in some cases.

        '';

      };

      nixos-test = mkOption {

        type = types.bool;

        default = true;

        description = "Standard requirement for NixOS integration tests";

      };

      uid-range = mkOption {

        type = types.bool;

        default = builtins.length (lib.attrNames containers) > 0;

        defaultText = lib.literalMD "`true` if containers are present.";

        description = "Containers use systemd-nspawn, which requires pid 0 inside of the sandbox. `uid-range` enables that.";

      };

      kvm = mkOption {

        type = types.bool;

        default = isLinux;

        defaultText = lib.literalMD "`true` if built to run on Linux.";

        description = "Whether Linux KVM virtualization is required when running this test. Can be disabled to allow emulated execution.";

      };

      apple-virt = mkOption {

        type = types.bool;

        default = isDarwin;

        defaultText = lib.literalMD "`true` if built to run on Darwin.";

        description = "Whether Apple virtualization functionality is required for running this test.";

      };

    };

  };

in

{

  options = {

    requiredFeatures = mkOption {

      description = "Builder features that are required for running this test.";

      example = lib.literalExpression ''

        {

          cuda = true;

          devnet = mkForce false;

        }

      '';

      type = types.submodule requiredFeaturesModuleType;

      default = { }; # this is necessary due to a bug in the module system.

    };

    passthru = mkOption {

      type = types.lazyAttrsOf types.raw;

      description = ''

      {

        name = "vm-test-run-${config.name}";

        requiredSystemFeatures = [

          "nixos-test"

        ]

        # Containers use systemd-nspawn, which requires pid 0 inside of the sandbox.

        ++ lib.optional (builtins.length (lib.attrNames containers) > 0) "uid-range"

        ++ lib.optional isLinux "kvm"

        ++ lib.optional isDarwin "apple-virt";

        requiredSystemFeatures = lib.attrNames (lib.filterAttrs (_: v: v) config.requiredFeatures);

        nativeBuildInputs = lib.optionals config.enableDebugHook [

          hostPkgs.openssh

{ config, lib, ... }:

{

  config,

  lib,

  pkgs,

  ...

}:

let

  sysctlOption = lib.mkOptionType {

      # the value below is used by default on several other distros.

      "fs.inotify.max_user_instances" = lib.mkDefault 524288;

      "fs.inotify.max_user_watches" = lib.mkDefault 524288;

      # Maximise address space randomisation.

      "vm.mmap_rnd_bits" = lib.mkMerge [

        (lib.mkIf pkgs.stdenv.hostPlatform.isAarch64 (

          let

            kernel = config.boot.kernelPackages.kernel;

            isYes = kernel.config.isYes or (_: false);

          in

          lib.mkDefault (

            if isYes "ARM64_64K_PAGES" then

              29

            else if isYes "ARM64_16K_PAGES" then

              31

            else

              33

          )

        ))

        (lib.mkIf pkgs.stdenv.hostPlatform.isx86_64 (lib.mkDefault 32))

      ];

      "vm.mmap_rnd_compat_bits" = lib.mkIf (

        pkgs.stdenv.hostPlatform.isx86_64 || pkgs.stdenv.hostPlatform.isAarch64

      ) (lib.mkDefault 16);

    };

  };

}

          "dbus"

          "broker"

        ];

        default = "dbus";

        default = "broker";

        description = ''

          The implementation to use for the message bus defined by the D-Bus specification.

          Can be either the classic dbus daemon or dbus-broker, which aims to provide high