nixos/*: add trivial defaultText to options where applicable

nixos/modules/config/fonts/fontdir.nix

@@ -39,6 +39,7 @@ in
       decompressFonts = mkOption {
         type = types.bool;
         default = config.programs.xwayland.enable;
+        defaultText = literalExpression "config.programs.xwayland.enable";
         description = ''
           Whether to decompress fonts in
           <filename>/run/current-system/sw/share/X11/fonts</filename>.

nixos/modules/config/gtk/gtk-icon-cache.nix

@@ -6,6 +6,7 @@ with lib;
     gtk.iconCache.enable = mkOption {
       type = types.bool;
       default = config.services.xserver.enable;
+      defaultText = literalExpression "config.services.xserver.enable";
       description = ''
         Whether to build icon theme caches for GTK applications.
       '';

nixos/modules/config/i18n.nix

@@ -14,6 +14,12 @@ with lib;
           allLocales = any (x: x == "all") config.i18n.supportedLocales;
           locales = config.i18n.supportedLocales;
         };
+        defaultText = literalExpression ''
+          pkgs.buildPackages.glibcLocales.override {
+            allLocales = any (x: x == "all") config.i18n.supportedLocales;
+            locales = config.i18n.supportedLocales;
+          }
+        '';
         example = literalExpression "pkgs.glibcLocales";
         description = ''
           Customized pkg.glibcLocales package.

nixos/modules/misc/meta.nix

@@ -37,7 +37,7 @@ in
         type = listOfMaintainers;
         internal = true;
         default = [];
-        example = [ lib.maintainers.all ];
+        example = literalExpression ''[ lib.maintainers.all ]'';
         description = ''
           List of maintainers of each module.  This option should be defined at
           most once per module.

nixos/modules/security/pam.nix

@@ -38,6 +38,7 @@ let
 
       p11Auth = mkOption {
         default = config.security.pam.p11.enable;
+        defaultText = literalExpression "config.security.pam.p11.enable";
         type = types.bool;
         description = ''
           If set, keys listed in
@@ -49,6 +50,7 @@ let
 
       u2fAuth = mkOption {
         default = config.security.pam.u2f.enable;
+        defaultText = literalExpression "config.security.pam.u2f.enable";
         type = types.bool;
         description = ''
           If set, users listed in
@@ -61,6 +63,7 @@ let
 
       yubicoAuth = mkOption {
         default = config.security.pam.yubico.enable;
+        defaultText = literalExpression "config.security.pam.yubico.enable";
         type = types.bool;
         description = ''
           If set, users listed in
@@ -83,6 +86,7 @@ let
 
       usbAuth = mkOption {
         default = config.security.pam.usb.enable;
+        defaultText = literalExpression "config.security.pam.usb.enable";
         type = types.bool;
         description = ''
           If set, users listed in
@@ -93,6 +97,7 @@ let
 
       otpwAuth = mkOption {
         default = config.security.pam.enableOTPW;
+        defaultText = literalExpression "config.security.pam.enableOTPW";
         type = types.bool;
         description = ''
           If set, the OTPW system will be used (if
@@ -126,6 +131,7 @@ let
 
       fprintAuth = mkOption {
         default = config.services.fprintd.enable;
+        defaultText = literalExpression "config.services.fprintd.enable";
         type = types.bool;
         description = ''
           If set, fingerprint reader will be used (if exists and
@@ -135,6 +141,7 @@ let
 
       oathAuth = mkOption {
         default = config.security.pam.oath.enable;
+        defaultText = literalExpression "config.security.pam.oath.enable";
         type = types.bool;
         description = ''
           If set, the OATH Toolkit will be used.
@@ -249,6 +256,7 @@ let
 
       pamMount = mkOption {
         default = config.security.pam.mount.enable;
+        defaultText = literalExpression "config.security.pam.mount.enable";
         type = types.bool;
         description = ''
           Enable PAM mount (pam_mount) system to mount fileystems on user login.

nixos/modules/services/audio/icecast.nix

@@ -50,6 +50,7 @@ in {
         type = types.nullOr types.str;
         description = "DNS name or IP address that will be used for the stream directory lookups or possibily the playlist generation if a Host header is not provided.";
         default = config.networking.domain;
+        defaultText = literalExpression "config.networking.domain";
       };
 
       admin = {

nixos/modules/services/audio/navidrome.nix

@@ -9,7 +9,7 @@ in {
   options = {
     services.navidrome = {
 
-      enable = mkEnableOption pkgs.navidrome.meta.description;
+      enable = mkEnableOption "Navidrome music server";
 
       settings = mkOption rec {
         type = settingsFormat.type;

nixos/modules/services/audio/ympd.nix

@@ -31,6 +31,7 @@ in {
         port = mkOption {
           type = types.int;
           default = config.services.mpd.network.port;
+          defaultText = literalExpression "config.services.mpd.network.port";
           description = "The port where MPD is listening.";
           example = 6600;
         };

nixos/modules/services/backup/bacula.nix

@@ -302,6 +302,7 @@ in {
 
       name = mkOption {
         default = "${config.networking.hostName}-fd";
+        defaultText = literalExpression ''"''${config.networking.hostName}-fd"'';
         type = types.str;
         description = ''
           The client name that must be used by the Director when connecting.
@@ -364,6 +365,7 @@ in {
 
       name = mkOption {
         default = "${config.networking.hostName}-sd";
+        defaultText = literalExpression ''"''${config.networking.hostName}-sd"'';
         type = types.str;
         description = ''
           Specifies the Name of the Storage daemon.
@@ -439,6 +441,7 @@ in {
 
       name = mkOption {
         default = "${config.networking.hostName}-dir";
+        defaultText = literalExpression ''"''${config.networking.hostName}-dir"'';
         type = types.str;
         description = ''
           The director name used by the system administrator. This directive is

nixos/modules/services/cluster/kubernetes/kubelet.nix

@@ -168,6 +168,7 @@ in
     hostname = mkOption {
       description = "Kubernetes kubelet hostname override.";
       default = config.networking.hostName;
+      defaultText = literalExpression "config.networking.hostName";
       type = str;
     };
 

nixos/modules/services/cluster/kubernetes/pki.nix

@@ -98,6 +98,7 @@ in
         the public and private keys respectively.
       '';
       default = "${config.services.cfssl.dataDir}/ca";
+      defaultText = literalExpression ''"''${config.services.cfssl.dataDir}/ca"'';
       type = str;
     };
 

nixos/modules/services/cluster/kubernetes/proxy.nix

@@ -37,6 +37,7 @@ in
     hostname = mkOption {
       description = "Kubernetes proxy hostname override.";
       default = config.networking.hostName;
+      defaultText = literalExpression "config.networking.hostName";
       type = str;
     };
 

nixos/modules/services/computing/slurm/slurm.nix

@@ -80,6 +80,7 @@ in
         dbdHost = mkOption {
           type = types.str;
           default = config.networking.hostName;
+          defaultText = literalExpression "config.networking.hostName";
           description = ''
             Hostname of the machine where <literal>slurmdbd</literal>
             is running (i.e. name returned by <literal>hostname -s</literal>).

nixos/modules/services/continuous-integration/github-runner.nix

@@ -58,6 +58,7 @@ in
       '';
       example = "nixos";
       default = config.networking.hostName;
+      defaultText = literalExpression "config.networking.hostName";
     };
 
     runnerGroup = mkOption {

nixos/modules/services/continuous-integration/hydra/default.nix

@@ -203,6 +203,7 @@ in
       buildMachinesFiles = mkOption {
         type = types.listOf types.path;
         default = optional (config.nix.buildMachines != []) "/etc/nix/machines";
+        defaultText = literalExpression ''optional (config.nix.buildMachines != []) "/etc/nix/machines"'';
         example = [ "/etc/nix/machines" "/var/lib/hydra/provisioner/machines" ];
         description = "List of files containing build machines.";
       };

nixos/modules/services/games/factorio.nix

@@ -75,8 +75,8 @@ in
         description = ''
           The name of the savegame that will be used by the server.
 
-          When not present in ${stateDir}/saves, a new map with default
-          settings will be generated before starting the service.
+          When not present in /var/lib/''${config.services.factorio.stateDirName}/saves,
+          a new map with default settings will be generated before starting the service.
         '';
       };
       # TODO Add more individual settings as nixos-options?

nixos/modules/services/logging/journalwatch.nix

@@ -74,6 +74,7 @@ in {
       mailFrom = mkOption {
         type = types.str;
         default = "journalwatch@${config.networking.hostName}";
+        defaultText = literalExpression ''"journalwatch@''${config.networking.hostName}"'';
         description = ''
           Mail address to send journalwatch reports from.
         '';

nixos/modules/services/logging/klogd.nix

@@ -10,6 +10,7 @@ with lib;
     services.klogd.enable = mkOption {
       type = types.bool;
       default = versionOlder (getVersion config.boot.kernelPackages.kernel) "3.5";
+      defaultText = literalExpression ''versionOlder (getVersion config.boot.kernelPackages.kernel) "3.5"'';
       description = ''
         Whether to enable klogd, the kernel log message processing
         daemon.  Since systemd handles logging of kernel messages on

nixos/modules/services/mail/opendkim.nix

@@ -55,6 +55,7 @@ in {
       domains = mkOption {
         type = types.str;
         default = "csl:${config.networking.hostName}";
+        defaultText = literalExpression ''"csl:''${config.networking.hostName}"'';
         example = "csl:example.com,mydomain.net";
         description = ''
           Local domains set (see <literal>opendkim(8)</literal> for more information on datasets).

nixos/modules/services/misc/etcd.nix

@@ -17,6 +17,7 @@ in {
     name = mkOption {
       description = "Etcd unique node name.";
       default = config.networking.hostName;
+      defaultText = literalExpression "config.networking.hostName";
       type = types.str;
     };
 

nixos/modules/services/misc/gitea.nix

@@ -299,7 +299,7 @@ in
               ENABLED = true;
               MAILER_TYPE = "sendmail";
               FROM = "do-not-reply@example.org";
-              SENDMAIL_PATH = "${pkgs.system-sendmail}/bin/sendmail";
+              SENDMAIL_PATH = "''${pkgs.system-sendmail}/bin/sendmail";
             };
             other = {
               SHOW_FOOTER_VERSION = false;

nixos/modules/services/misc/gitlab.nix

@@ -475,6 +475,7 @@ in {
       host = mkOption {
         type = types.str;
         default = config.networking.hostName;
+        defaultText = literalExpression "config.networking.hostName";
         description = "GitLab host name. Used e.g. for copy-paste URLs.";
       };
 
@@ -534,6 +535,7 @@ in {
         host = mkOption {
           type = types.str;
           default = config.services.gitlab.host;
+          defaultText = literalExpression "config.services.gitlab.host";
           description = "GitLab container registry host name.";
         };
         port = mkOption {

nixos/modules/services/misc/matrix-appservice-discord.nix

@@ -98,6 +98,9 @@ in {
       serviceDependencies = mkOption {
         type = with types; listOf str;
         default = optional config.services.matrix-synapse.enable "matrix-synapse.service";
+        defaultText = literalExpression ''
+          optional config.services.matrix-synapse.enable "matrix-synapse.service"
+        '';
         description = ''
           List of Systemd services to require and wait for when starting the application service,
           such as the Matrix homeserver if it's running on the same host.

nixos/modules/services/misc/matrix-synapse.nix

@@ -227,6 +227,7 @@ in {
         type = types.str;
         example = "example.com";
         default = config.networking.hostName;
+        defaultText = literalExpression "config.networking.hostName";
         description = ''
           The domain name of the server, with optional explicit port.
           This is used by remote servers to look up the server address.
@@ -379,6 +380,11 @@ in {
         default = if versionAtLeast config.system.stateVersion "18.03"
           then "psycopg2"
           else "sqlite3";
+        defaultText = literalExpression ''
+          if versionAtLeast config.system.stateVersion "18.03"
+            then "psycopg2"
+            else "sqlite3"
+        '';
         description = ''
           The database engine name. Can be sqlite or psycopg2.
         '';

nixos/modules/services/misc/mautrix-telegram.nix

@@ -108,6 +108,9 @@ in {
       serviceDependencies = mkOption {
         type = with types; listOf str;
         default = optional config.services.matrix-synapse.enable "matrix-synapse.service";
+        defaultText = literalExpression ''
+          optional config.services.matrix-synapse.enable "matrix-synapse.service"
+        '';
         description = ''
           List of Systemd services to require and wait for when starting the application service.
         '';

nixos/modules/services/misc/moonraker.nix

@@ -18,6 +18,7 @@ in {
       klipperSocket = mkOption {
         type = types.path;
         default = config.services.klipper.apiSocket;
+        defaultText = literalExpression "config.services.klipper.apiSocket";
         description = "Path to Klipper's API socket.";
       };
 

nixos/modules/services/misc/mx-puppet-discord.nix

@@ -67,6 +67,9 @@ in {
       serviceDependencies = mkOption {
         type = with types; listOf str;
         default = optional config.services.matrix-synapse.enable "matrix-synapse.service";
+        defaultText = literalExpression ''
+          optional config.services.matrix-synapse.enable "matrix-synapse.service"
+        '';
         description = ''
           List of Systemd services to require and wait for when starting the application service.
         '';

nixos/modules/services/misc/sourcehut/default.nix

@@ -71,6 +71,9 @@ in
     originBase = mkOption {
       type = types.str;
       default = with config.networking; hostName + lib.optionalString (domain != null) ".${domain}";
+      defaultText = literalExpression ''
+        with config.networking; hostName + optionalString (domain != null) ".''${domain}"
+      '';
       description = ''
         Host name used by reverse-proxy and for default settings. Will host services at git."''${originBase}". For example: git.sr.ht
       '';

nixos/modules/services/misc/xmrig.nix

@@ -18,6 +18,7 @@ with lib;
       package = mkOption {
         type = types.package;
         default = pkgs.xmrig;
+        defaultText = literalExpression "pkgs.xmrig";
         example = literalExpression "pkgs.xmrig-mo";
         description = "XMRig package to use.";
       };

nixos/modules/services/monitoring/graphite.nix

@@ -324,6 +324,7 @@ in {
 
       mongoUrl = mkOption {
         default = "mongodb://${config.services.mongodb.bind_ip}:27017/seyren";
+        defaultText = literalExpression ''"mongodb://''${config.services.mongodb.bind_ip}:27017/seyren"'';
         description = "Mongodb connection string.";
         type = types.str;
       };

nixos/modules/services/monitoring/nagios.nix

@@ -131,6 +131,7 @@ in
       validateConfig = mkOption {
         type = types.bool;
         default = pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform;
+        defaultText = literalExpression "pkgs.stdenv.hostPlatform == pkgs.stdenv.buildPlatform";
         description = "if true, the syntax of the nagios configuration file is checked at build time";
       };
 

nixos/modules/services/monitoring/parsedmarc.nix

@@ -93,6 +93,7 @@ in
         dashboard = lib.mkOption {
           type = lib.types.bool;
           default = config.services.grafana.enable;
+          defaultText = lib.literalExpression "config.services.grafana.enable";
           description = ''
             Whether the official parsedmarc grafana dashboard should
             be provisioned to the local grafana instance.

nixos/modules/services/monitoring/smartd.nix

@@ -125,6 +125,7 @@ in
         mail = {
           enable = mkOption {
             default = config.services.mail.sendmailSetuidWrapper != null;
+            defaultText = literalExpression "config.services.mail.sendmailSetuidWrapper != null";
             type = types.bool;
             description = "Whenever to send e-mail notifications.";
           };
@@ -169,12 +170,14 @@ in
         x11 = {
           enable = mkOption {
             default = config.services.xserver.enable;
+            defaultText = literalExpression "config.services.xserver.enable";
             type = types.bool;
             description = "Whenever to send X11 xmessage notifications.";
           };
 
           display = mkOption {
             default = ":${toString config.services.xserver.display}";
+            defaultText = literalExpression ''":''${toString config.services.xserver.display}"'';
             type = types.str;
             description = "DISPLAY to send X11 notifications to.";
           };