diff options
Diffstat (limited to 'nixos/modules/services/misc/nix-daemon.nix')
| -rw-r--r-- | nixos/modules/services/misc/nix-daemon.nix | 818 |
1 files changed, 818 insertions, 0 deletions
diff --git a/nixos/modules/services/misc/nix-daemon.nix b/nixos/modules/services/misc/nix-daemon.nix new file mode 100644 index 00000000000..2b21df91b82 --- /dev/null +++ b/nixos/modules/services/misc/nix-daemon.nix @@ -0,0 +1,818 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + + cfg = config.nix; + + nixPackage = cfg.package.out; + + isNixAtLeast = versionAtLeast (getVersion nixPackage); + + makeNixBuildUser = nr: { + name = "nixbld${toString nr}"; + value = { + description = "Nix build user ${toString nr}"; + + /* + For consistency with the setgid(2), setuid(2), and setgroups(2) + calls in `libstore/build.cc', don't add any supplementary group + here except "nixbld". + */ + uid = builtins.add config.ids.uids.nixbld nr; + isSystemUser = true; + group = "nixbld"; + extraGroups = [ "nixbld" ]; + }; + }; + + nixbldUsers = listToAttrs (map makeNixBuildUser (range 1 cfg.nrBuildUsers)); + + nixConf = + assert isNixAtLeast "2.2"; + let + + mkValueString = v: + if v == null then "" + else if isInt v then toString v + else if isBool v then boolToString v + else if isFloat v then floatToString v + else if isList v then toString v + else if isDerivation v then toString v + else if builtins.isPath v then toString v + else if isString v then v + else if isCoercibleToString v then toString v + else abort "The nix conf value: ${toPretty {} v} can not be encoded"; + + mkKeyValue = k: v: "${escape [ "=" ] k} = ${mkValueString v}"; + + mkKeyValuePairs = attrs: concatStringsSep "\n" (mapAttrsToList mkKeyValue attrs); + + in + pkgs.writeTextFile { + name = "nix.conf"; + text = '' + # WARNING: this file is generated from the nix.* options in + # your NixOS configuration, typically + # /etc/nixos/configuration.nix. Do not edit it! + ${mkKeyValuePairs cfg.settings} + ${cfg.extraOptions} + ''; + checkPhase = + if pkgs.stdenv.hostPlatform != pkgs.stdenv.buildPlatform then '' + echo "Ignoring validation for cross-compilation" + '' + else '' + echo "Validating generated nix.conf" + ln -s $out ./nix.conf + set -e + set +o pipefail + NIX_CONF_DIR=$PWD \ + ${cfg.package}/bin/nix show-config ${optionalString (isNixAtLeast "2.3pre") "--no-net"} \ + ${optionalString (isNixAtLeast "2.4pre") "--option experimental-features nix-command"} \ + |& sed -e 's/^warning:/error:/' \ + | (! grep '${if cfg.checkConfig then "^error:" else "^error: unknown setting"}') + set -o pipefail + ''; + }; + + legacyConfMappings = { + useSandbox = "sandbox"; + buildCores = "cores"; + maxJobs = "max-jobs"; + sandboxPaths = "extra-sandbox-paths"; + binaryCaches = "substituters"; + trustedBinaryCaches = "trusted-substituters"; + binaryCachePublicKeys = "trusted-public-keys"; + autoOptimiseStore = "auto-optimise-store"; + requireSignedBinaryCaches = "require-sigs"; + trustedUsers = "trusted-users"; + allowedUsers = "allowed-users"; + systemFeatures = "system-features"; + }; + + semanticConfType = with types; + let + confAtom = nullOr + (oneOf [ + bool + int + float + str + path + package + ]) // { + description = "Nix config atom (null, bool, int, float, str, path or package)"; + }; + in + attrsOf (either confAtom (listOf confAtom)); + +in + +{ + imports = [ + (mkRenamedOptionModule [ "nix" "useChroot" ] [ "nix" "useSandbox" ]) + (mkRenamedOptionModule [ "nix" "chrootDirs" ] [ "nix" "sandboxPaths" ]) + (mkRenamedOptionModule [ "nix" "daemonIONiceLevel" ] [ "nix" "daemonIOSchedPriority" ]) + (mkRemovedOptionModule [ "nix" "daemonNiceLevel" ] "Consider nix.daemonCPUSchedPolicy instead.") + ] ++ mapAttrsToList (oldConf: newConf: mkRenamedOptionModule [ "nix" oldConf ] [ "nix" "settings" newConf ]) legacyConfMappings; + + ###### interface + + options = { + + nix = { + + enable = mkOption { + type = types.bool; + default = true; + description = '' + Whether to enable Nix. + Disabling Nix makes the system hard to modify and the Nix programs and configuration will not be made available by NixOS itself. + ''; + }; + + package = mkOption { + type = types.package; + default = pkgs.nix; + defaultText = literalExpression "pkgs.nix"; + description = '' + This option specifies the Nix package instance to use throughout the system. + ''; + }; + + distributedBuilds = mkOption { + type = types.bool; + default = false; + description = '' + Whether to distribute builds to the machines listed in + <option>nix.buildMachines</option>. + ''; + }; + + daemonCPUSchedPolicy = mkOption { + type = types.enum [ "other" "batch" "idle" ]; + default = "other"; + example = "batch"; + description = '' + Nix daemon process CPU scheduling policy. This policy propagates to + build processes. <literal>other</literal> is the default scheduling + policy for regular tasks. The <literal>batch</literal> policy is + similar to <literal>other</literal>, but optimised for + non-interactive tasks. <literal>idle</literal> is for extremely + low-priority tasks that should only be run when no other task + requires CPU time. + + Please note that while using the <literal>idle</literal> policy may + greatly improve responsiveness of a system performing expensive + builds, it may also slow down and potentially starve crucial + configuration updates during load. + + <literal>idle</literal> may therefore be a sensible policy for + systems that experience only intermittent phases of high CPU load, + such as desktop or portable computers used interactively. Other + systems should use the <literal>other</literal> or + <literal>batch</literal> policy instead. + + For more fine-grained resource control, please refer to + <citerefentry><refentrytitle>systemd.resource-control + </refentrytitle><manvolnum>5</manvolnum></citerefentry> and adjust + <option>systemd.services.nix-daemon</option> directly. + ''; + }; + + daemonIOSchedClass = mkOption { + type = types.enum [ "best-effort" "idle" ]; + default = "best-effort"; + example = "idle"; + description = '' + Nix daemon process I/O scheduling class. This class propagates to + build processes. <literal>best-effort</literal> is the default + class for regular tasks. The <literal>idle</literal> class is for + extremely low-priority tasks that should only perform I/O when no + other task does. + + Please note that while using the <literal>idle</literal> scheduling + class can improve responsiveness of a system performing expensive + builds, it might also slow down or starve crucial configuration + updates during load. + + <literal>idle</literal> may therefore be a sensible class for + systems that experience only intermittent phases of high I/O load, + such as desktop or portable computers used interactively. Other + systems should use the <literal>best-effort</literal> class. + ''; + }; + + daemonIOSchedPriority = mkOption { + type = types.int; + default = 0; + example = 1; + description = '' + Nix daemon process I/O scheduling priority. This priority propagates + to build processes. The supported priorities depend on the + scheduling policy: With idle, priorities are not used in scheduling + decisions. best-effort supports values in the range 0 (high) to 7 + (low). + ''; + }; + + buildMachines = mkOption { + type = types.listOf (types.submodule { + options = { + hostName = mkOption { + type = types.str; + example = "nixbuilder.example.org"; + description = '' + The hostname of the build machine. + ''; + }; + system = mkOption { + type = types.nullOr types.str; + default = null; + example = "x86_64-linux"; + description = '' + The system type the build machine can execute derivations on. + Either this attribute or <varname>systems</varname> must be + present, where <varname>system</varname> takes precedence if + both are set. + ''; + }; + systems = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "x86_64-linux" "aarch64-linux" ]; + description = '' + The system types the build machine can execute derivations on. + Either this attribute or <varname>system</varname> must be + present, where <varname>system</varname> takes precedence if + both are set. + ''; + }; + sshUser = mkOption { + type = types.nullOr types.str; + default = null; + example = "builder"; + description = '' + The username to log in as on the remote host. This user must be + able to log in and run nix commands non-interactively. It must + also be privileged to build derivations, so must be included in + <option>nix.settings.trusted-users</option>. + ''; + }; + sshKey = mkOption { + type = types.nullOr types.str; + default = null; + example = "/root/.ssh/id_buildhost_builduser"; + description = '' + The path to the SSH private key with which to authenticate on + the build machine. The private key must not have a passphrase. + If null, the building user (root on NixOS machines) must have an + appropriate ssh configuration to log in non-interactively. + + Note that for security reasons, this path must point to a file + in the local filesystem, *not* to the nix store. + ''; + }; + maxJobs = mkOption { + type = types.int; + default = 1; + description = '' + The number of concurrent jobs the build machine supports. The + build machine will enforce its own limits, but this allows hydra + to schedule better since there is no work-stealing between build + machines. + ''; + }; + speedFactor = mkOption { + type = types.int; + default = 1; + description = '' + The relative speed of this builder. This is an arbitrary integer + that indicates the speed of this builder, relative to other + builders. Higher is faster. + ''; + }; + mandatoryFeatures = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "big-parallel" ]; + description = '' + A list of features mandatory for this builder. The builder will + be ignored for derivations that don't require all features in + this list. All mandatory features are automatically included in + <varname>supportedFeatures</varname>. + ''; + }; + supportedFeatures = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "kvm" "big-parallel" ]; + description = '' + A list of features supported by this builder. The builder will + be ignored for derivations that require features not in this + list. + ''; + }; + publicHostKey = mkOption { + type = types.nullOr types.str; + default = null; + description = '' + The (base64-encoded) public host key of this builder. The field + is calculated via <command>base64 -w0 /etc/ssh/ssh_host_type_key.pub</command>. + If null, SSH will use its regular known-hosts file when connecting. + ''; + }; + }; + }); + default = [ ]; + description = '' + This option lists the machines to be used if distributed builds are + enabled (see <option>nix.distributedBuilds</option>). + Nix will perform derivations on those machines via SSH by copying the + inputs to the Nix store on the remote machine, starting the build, + then copying the output back to the local Nix store. + ''; + }; + + # Environment variables for running Nix. + envVars = mkOption { + type = types.attrs; + internal = true; + default = { }; + description = "Environment variables used by Nix."; + }; + + nrBuildUsers = mkOption { + type = types.int; + description = '' + Number of <literal>nixbld</literal> user accounts created to + perform secure concurrent builds. If you receive an error + message saying that “all build users are currently in use”, + you should increase this value. + ''; + }; + + readOnlyStore = mkOption { + type = types.bool; + default = true; + description = '' + If set, NixOS will enforce the immutability of the Nix store + by making <filename>/nix/store</filename> a read-only bind + mount. Nix will automatically make the store writable when + needed. + ''; + }; + + nixPath = mkOption { + type = types.listOf types.str; + default = [ + "nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos" + "nixos-config=/etc/nixos/configuration.nix" + "/nix/var/nix/profiles/per-user/root/channels" + ]; + description = '' + The default Nix expression search path, used by the Nix + evaluator to look up paths enclosed in angle brackets + (e.g. <literal><nixpkgs></literal>). + ''; + }; + + checkConfig = mkOption { + type = types.bool; + default = true; + description = '' + If enabled (the default), checks for data type mismatches and that Nix + can parse the generated nix.conf. + ''; + }; + + registry = mkOption { + type = types.attrsOf (types.submodule ( + let + referenceAttrs = with types; attrsOf (oneOf [ + str + int + bool + package + ]); + in + { config, name, ... }: + { + options = { + from = mkOption { + type = referenceAttrs; + example = { type = "indirect"; id = "nixpkgs"; }; + description = "The flake reference to be rewritten."; + }; + to = mkOption { + type = referenceAttrs; + example = { type = "github"; owner = "my-org"; repo = "my-nixpkgs"; }; + description = "The flake reference <option>from></option> is rewritten to."; + }; + flake = mkOption { + type = types.nullOr types.attrs; + default = null; + example = literalExpression "nixpkgs"; + description = '' + The flake input <option>from></option> is rewritten to. + ''; + }; + exact = mkOption { + type = types.bool; + default = true; + description = '' + Whether the <option>from</option> reference needs to match exactly. If set, + a <option>from</option> reference like <literal>nixpkgs</literal> does not + match with a reference like <literal>nixpkgs/nixos-20.03</literal>. + ''; + }; + }; + config = { + from = mkDefault { type = "indirect"; id = name; }; + to = mkIf (config.flake != null) (mkDefault + { + type = "path"; + path = config.flake.outPath; + } // filterAttrs + (n: _: n == "lastModified" || n == "rev" || n == "revCount" || n == "narHash") + config.flake); + }; + } + )); + default = { }; + description = '' + A system-wide flake registry. + ''; + }; + + extraOptions = mkOption { + type = types.lines; + default = ""; + example = '' + keep-outputs = true + keep-derivations = true + ''; + description = "Additional text appended to <filename>nix.conf</filename>."; + }; + + settings = mkOption { + type = types.submodule { + freeformType = semanticConfType; + + options = { + max-jobs = mkOption { + type = types.either types.int (types.enum [ "auto" ]); + default = "auto"; + example = 64; + description = '' + This option defines the maximum number of jobs that Nix will try to + build in parallel. The default is auto, which means it will use all + available logical cores. It is recommend to set it to the total + number of logical cores in your system (e.g., 16 for two CPUs with 4 + cores each and hyper-threading). + ''; + }; + + auto-optimise-store = mkOption { + type = types.bool; + default = false; + example = true; + description = '' + If set to true, Nix automatically detects files in the store that have + identical contents, and replaces them with hard links to a single copy. + This saves disk space. If set to false (the default), you can still run + nix-store --optimise to get rid of duplicate files. + ''; + }; + + cores = mkOption { + type = types.int; + default = 0; + example = 64; + description = '' + This option defines the maximum number of concurrent tasks during + one build. It affects, e.g., -j option for make. + The special value 0 means that the builder should use all + available CPU cores in the system. Some builds may become + non-deterministic with this option; use with care! Packages will + only be affected if enableParallelBuilding is set for them. + ''; + }; + + sandbox = mkOption { + type = types.either types.bool (types.enum [ "relaxed" ]); + default = true; + description = '' + If set, Nix will perform builds in a sandboxed environment that it + will set up automatically for each build. This prevents impurities + in builds by disallowing access to dependencies outside of the Nix + store by using network and mount namespaces in a chroot environment. + This is enabled by default even though it has a possible performance + impact due to the initial setup time of a sandbox for each build. It + doesn't affect derivation hashes, so changing this option will not + trigger a rebuild of packages. + ''; + }; + + extra-sandbox-paths = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "/dev" "/proc" ]; + description = '' + Directories from the host filesystem to be included + in the sandbox. + ''; + }; + + substituters = mkOption { + type = types.listOf types.str; + description = '' + List of binary cache URLs used to obtain pre-built binaries + of Nix packages. + + By default https://cache.nixos.org/ is added. + ''; + }; + + trusted-substituters = mkOption { + type = types.listOf types.str; + default = [ ]; + example = [ "https://hydra.nixos.org/" ]; + description = '' + List of binary cache URLs that non-root users can use (in + addition to those specified using + <option>nix.settings.substituters</option>) by passing + <literal>--option binary-caches</literal> to Nix commands. + ''; + }; + + require-sigs = mkOption { + type = types.bool; + default = true; + description = '' + If enabled (the default), Nix will only download binaries from binary caches if + they are cryptographically signed with any of the keys listed in + <option>nix.settings.trusted-public-keys</option>. If disabled, signatures are neither + required nor checked, so it's strongly recommended that you use only + trustworthy caches and https to prevent man-in-the-middle attacks. + ''; + }; + + trusted-public-keys = mkOption { + type = types.listOf types.str; + example = [ "hydra.nixos.org-1:CNHJZBh9K4tP3EKF6FkkgeVYsS3ohTl+oS0Qa8bezVs=" ]; + description = '' + List of public keys used to sign binary caches. If + <option>nix.settings.trusted-public-keys</option> is enabled, + then Nix will use a binary from a binary cache if and only + if it is signed by <emphasis>any</emphasis> of the keys + listed here. By default, only the key for + <uri>cache.nixos.org</uri> is included. + ''; + }; + + trusted-users = mkOption { + type = types.listOf types.str; + default = [ "root" ]; + example = [ "root" "alice" "@wheel" ]; + description = '' + A list of names of users that have additional rights when + connecting to the Nix daemon, such as the ability to specify + additional binary caches, or to import unsigned NARs. You + can also specify groups by prefixing them with + <literal>@</literal>; for instance, + <literal>@wheel</literal> means all users in the wheel + group. + ''; + }; + + system-features = mkOption { + type = types.listOf types.str; + example = [ "kvm" "big-parallel" "gccarch-skylake" ]; + description = '' + The set of features supported by the machine. Derivations + can express dependencies on system features through the + <literal>requiredSystemFeatures</literal> attribute. + + By default, pseudo-features <literal>nixos-test</literal>, <literal>benchmark</literal>, + and <literal>big-parallel</literal> used in Nixpkgs are set, <literal>kvm</literal> + is also included in it is avaliable. + ''; + }; + + allowed-users = mkOption { + type = types.listOf types.str; + default = [ "*" ]; + example = [ "@wheel" "@builders" "alice" "bob" ]; + description = '' + A list of names of users (separated by whitespace) that are + allowed to connect to the Nix daemon. As with + <option>nix.settings.trusted-users</option>, you can specify groups by + prefixing them with <literal>@</literal>. Also, you can + allow all users by specifying <literal>*</literal>. The + default is <literal>*</literal>. Note that trusted users are + always allowed to connect. + ''; + }; + }; + }; + default = { }; + example = literalExpression '' + { + use-sandbox = true; + show-trace = true; + + system-features = [ "big-parallel" "kvm" "recursive-nix" ]; + sandbox-paths = { "/bin/sh" = "''${pkgs.busybox-sandbox-shell.out}/bin/busybox"; }; + } + ''; + description = '' + Configuration for Nix, see + <link xlink:href="https://nixos.org/manual/nix/stable/#sec-conf-file"/> or + <citerefentry> + <refentrytitle>nix.conf</refentrytitle> + <manvolnum>5</manvolnum> + </citerefentry> for avalaible options. + The value declared here will be translated directly to the key-value pairs Nix expects. + </para> + <para> + You can use <command>nix-instantiate --eval --strict '<nixpkgs/nixos>' -A config.nix.settings</command> + to view the current value. By default it is empty. + </para> + <para> + Nix configurations defined under <option>nix.*</option> will be translated and applied to this + option. In addition, configuration specified in <option>nix.extraOptions</option> which will be appended + verbatim to the resulting config file. + ''; + }; + }; + }; + + + ###### implementation + + config = mkIf cfg.enable { + environment.systemPackages = + [ + nixPackage + pkgs.nix-info + ] + ++ optional (config.programs.bash.enableCompletion) pkgs.nix-bash-completions; + + environment.etc."nix/nix.conf".source = nixConf; + + environment.etc."nix/registry.json".text = builtins.toJSON { + version = 2; + flakes = mapAttrsToList (n: v: { inherit (v) from to exact; }) cfg.registry; + }; + + # List of machines for distributed Nix builds in the format + # expected by build-remote.pl. + environment.etc."nix/machines" = mkIf (cfg.buildMachines != [ ]) { + text = + concatMapStrings + (machine: + (concatStringsSep " " ([ + "${optionalString (machine.sshUser != null) "${machine.sshUser}@"}${machine.hostName}" + (if machine.system != null then machine.system else if machine.systems != [ ] then concatStringsSep "," machine.systems else "-") + (if machine.sshKey != null then machine.sshKey else "-") + (toString machine.maxJobs) + (toString machine.speedFactor) + (concatStringsSep "," (machine.supportedFeatures ++ machine.mandatoryFeatures)) + (concatStringsSep "," machine.mandatoryFeatures) + ] + ++ optional (isNixAtLeast "2.4pre") (if machine.publicHostKey != null then machine.publicHostKey else "-"))) + + "\n" + ) + cfg.buildMachines; + }; + + assertions = + let badMachine = m: m.system == null && m.systems == [ ]; + in + [ + { + assertion = !(any badMachine cfg.buildMachines); + message = '' + At least one system type (via <varname>system</varname> or + <varname>systems</varname>) must be set for every build machine. + Invalid machine specifications: + '' + " " + + (concatStringsSep "\n " + (map (m: m.hostName) + (filter (badMachine) cfg.buildMachines))); + } + ]; + + systemd.packages = [ nixPackage ]; + + systemd.sockets.nix-daemon.wantedBy = [ "sockets.target" ]; + + systemd.services.nix-daemon = + { + path = [ nixPackage pkgs.util-linux config.programs.ssh.package ] + ++ optionals cfg.distributedBuilds [ pkgs.gzip ]; + + environment = cfg.envVars + // { CURL_CA_BUNDLE = "/etc/ssl/certs/ca-certificates.crt"; } + // config.networking.proxy.envVars; + + unitConfig.RequiresMountsFor = "/nix/store"; + + serviceConfig = + { + CPUSchedulingPolicy = cfg.daemonCPUSchedPolicy; + IOSchedulingClass = cfg.daemonIOSchedClass; + IOSchedulingPriority = cfg.daemonIOSchedPriority; + LimitNOFILE = 4096; + }; + + restartTriggers = [ nixConf ]; + + # `stopIfChanged = false` changes to switch behavior + # from stop -> update units -> start + # to update units -> restart + # + # The `stopIfChanged` setting therefore controls a trade-off between a + # more predictable lifecycle, which runs the correct "version" of + # the `ExecStop` line, and on the other hand the availability of + # sockets during the switch, as the effectiveness of the stop operation + # depends on the socket being stopped as well. + # + # As `nix-daemon.service` does not make use of `ExecStop`, we prefer + # to keep the socket up and available. This is important for machines + # that run Nix-based services, such as automated build, test, and deploy + # services, that expect the daemon socket to be available at all times. + # + # Notably, the Nix client does not retry on failure to connect to the + # daemon socket, and the in-process RemoteStore instance will disable + # itself. This makes retries infeasible even for services that are + # aware of the issue. Failure to connect can affect not only new client + # processes, but also new RemoteStore instances in existing processes, + # as well as existing RemoteStore instances that have not saturated + # their connection pool. + # + # Also note that `stopIfChanged = true` does not kill existing + # connection handling daemons, as one might wish to happen before a + # breaking Nix upgrade (which is rare). The daemon forks that handle + # the individual connections split off into their own sessions, causing + # them not to be stopped by systemd. + # If a Nix upgrade does require all existing daemon processes to stop, + # nix-daemon must do so on its own accord, and only when the new version + # starts and detects that Nix's persistent state needs an upgrade. + stopIfChanged = false; + + }; + + # Set up the environment variables for running Nix. + environment.sessionVariables = cfg.envVars // { NIX_PATH = cfg.nixPath; }; + + environment.extraInit = + '' + if [ -e "$HOME/.nix-defexpr/channels" ]; then + export NIX_PATH="$HOME/.nix-defexpr/channels''${NIX_PATH:+:$NIX_PATH}" + fi + ''; + + nix.nrBuildUsers = mkDefault (max 32 (if cfg.settings.max-jobs == "auto" then 0 else cfg.settings.max-jobs)); + + users.users = nixbldUsers; + + services.xserver.displayManager.hiddenUsers = attrNames nixbldUsers; + + system.activationScripts.nix = stringAfter [ "etc" "users" ] + '' + install -m 0755 -d /nix/var/nix/{gcroots,profiles}/per-user + + # Subscribe the root user to the NixOS channel by default. + if [ ! -e "/root/.nix-channels" ]; then + echo "${config.system.defaultChannel} nixos" > "/root/.nix-channels" + fi + ''; + + # Legacy configuration conversion. + nix.settings = mkMerge [ + { + trusted-public-keys = [ "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=" ]; + substituters = mkAfter [ "https://cache.nixos.org/" ]; + + system-features = mkDefault ( + [ "nixos-test" "benchmark" "big-parallel" "kvm" ] ++ + optionals (pkgs.hostPlatform ? gcc.arch) ( + # a builder can run code for `gcc.arch` and inferior architectures + [ "gccarch-${pkgs.hostPlatform.gcc.arch}" ] ++ + map (x: "gccarch-${x}") systems.architectures.inferiors.${pkgs.hostPlatform.gcc.arch} + ) + ); + } + + (mkIf (!cfg.distributedBuilds) { builders = null; }) + + (mkIf (isNixAtLeast "2.3pre") { sandbox-fallback = false; }) + ]; + + }; + +} |