nixos/treewide: remove boolean examples for options

They contain no useful information and increase the length of the
autogenerated options documentation.

See discussion in #18816.

nixos/modules/installer/cd-dvd/iso-image.nix

@@ -172,7 +172,6 @@ in
 
     isoImage.includeSystemBuildDependencies = mkOption {
       default = false;
-      example = true;
       description = ''
         Set this option to include all the needed sources etc in the
         image. It significantly increases image size. Use that when

nixos/modules/programs/adb.nix

@@ -10,7 +10,6 @@ with lib;
     programs.adb = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to configure system to use Android Debug Bridge (adb).

nixos/modules/programs/gphoto2.nix

@@ -10,7 +10,6 @@ with lib;
     programs.gphoto2 = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to configure system to use gphoto2.

nixos/modules/programs/mosh.nix

@@ -14,7 +14,6 @@ in
         Whether to enable mosh. Note, this will open ports in your firewall!
       '';
       default = false;
-      example = true;
       type = lib.types.bool;
     };
   };

nixos/modules/programs/ssmtp.nix

@@ -22,7 +22,6 @@ in
       directDelivery = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Use the trivial Mail Transfer Agent (MTA)
           <command>ssmtp</command> package to allow programs to send
@@ -65,7 +64,6 @@ in
       useTLS = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether TLS should be used to connect to the default mail
           server.
@@ -75,7 +73,6 @@ in
       useSTARTTLS = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether the STARTTLS should be used to connect to the default
           mail server.  (This is needed for TLS-capable mail servers

nixos/modules/programs/tmux.nix

@@ -65,7 +65,6 @@ in {
 
       aggressiveResize = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Resize the window to the size of the smallest session for which it is the current window.
@@ -81,14 +80,12 @@ in {
 
       clock24 = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Use 24 hour clock.";
       };
 
       customPaneNavigationAndResize = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Override the hjkl and HJKL bindings for pane navigation and resizing in VI mode.";
       };
@@ -124,14 +121,12 @@ in {
 
       newSession = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Automatically spawn a session if trying to attach and none are running.";
       };
 
       reverseSplit = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Reverse the window split shortcuts.";
       };

nixos/modules/programs/vim.nix

@@ -9,7 +9,6 @@ in {
     defaultEditor = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         When enabled, installs vim and configures vim to be the default editor
         using the EDITOR environment variable.

nixos/modules/security/grsecurity.nix

@@ -21,7 +21,6 @@ in
 
     enable = mkOption {
       type = types.bool;
-      example = true;
       default = false;
       description = ''
         Enable grsecurity/PaX.
@@ -30,7 +29,6 @@ in
 
     lockTunables = mkOption {
       type = types.bool;
-      example = false;
       default = true;
       description = ''
         Whether to automatically lock grsecurity tunables
@@ -43,7 +41,6 @@ in
 
     disableEfiRuntimeServices = mkOption {
       type = types.bool;
-      example = false;
       default = true;
       description = ''
         Whether to disable access to EFI runtime services.  Enabling EFI runtime

nixos/modules/services/backup/rsnapshot.nix

@@ -26,7 +26,6 @@ in
       enableManualRsnapshot = mkOption {
         description = "Whether to enable manual usage of the rsnapshot command with this module.";
         default = true;
-        example = false;
         type = types.bool;
       };
 

nixos/modules/services/computing/boinc/client.nix

@@ -12,7 +12,6 @@ in
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether to enable the BOINC distributed computing client. If this
           option is set to true, the boinc_client daemon will be run as a
@@ -41,7 +40,6 @@ in
       allowRemoteGuiRpc = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           If set to true, any remote host can connect to and control this BOINC
           client (subject to password authentication). If instead set to false,

nixos/modules/services/databases/cassandra.nix

@@ -310,7 +310,6 @@ in {
     autoBootstrap = mkOption {
       description = "It makes new (non-seed) nodes automatically migrate the right data to themselves.";
       default = true;
-      example = true;
       type = types.bool;
     };
     streamingSocketTimoutInMS = mkOption {

nixos/modules/services/databases/openldap.nix

@@ -25,7 +25,6 @@ in
         description = "
           Whether to enable the ldap server.
         ";
-        example = true;
       };
 
       user = mkOption {

nixos/modules/services/editors/emacs.nix

@@ -21,7 +21,6 @@ in {
     enable = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Whether to enable a user service for the Emacs daemon. Use <literal>emacsclient</literal> to connect to the
         daemon. If <literal>true</literal>, <varname>services.emacs.install</varname> is
@@ -32,7 +31,6 @@ in {
     install = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Whether to install a user service for the Emacs daemon. Once
         the service is started, use emacsclient to connect to the
@@ -57,7 +55,6 @@ in {
     defaultEditor = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         When enabled, configures emacsclient to be the default editor
         using the EDITOR environment variable.

nixos/modules/services/mail/offlineimap.nix

@@ -12,7 +12,6 @@ in {
     install = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Whether to install a user service for Offlineimap. Once
         the service is started, emails will be fetched automatically.

nixos/modules/services/misc/ihaskell.nix

@@ -16,7 +16,6 @@ in
     services.ihaskell = {
       enable = mkOption {
         default = false;
-        example = true;
         description = "Autostart an IHaskell notebook service.";
       };
 

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

@@ -148,7 +148,6 @@ in {
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether to enable the Taskwarrior server.
 

nixos/modules/services/monitoring/arbtt.nix

@@ -10,7 +10,6 @@ in {
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Enable the arbtt statistics capture service.
         '';

nixos/modules/services/networking/aiccu.nix

@@ -35,7 +35,6 @@ in {
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Enable aiccu IPv6 over IPv4 SiXXs tunnel";
       };
 
@@ -88,21 +87,18 @@ in {
       verbose = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Be verbose?";
       };
 
       automatic = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = "Automatic Login and Tunnel activation";
       };
 
       requireTLS = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           When set to true, if TLS is not supported on the server
           the TIC transaction will fail.
@@ -124,7 +120,6 @@ in {
       defaultRoute = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = "Add a default route";
       };
 
@@ -138,7 +133,6 @@ in {
       makeHeartBeats = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = ''
           In general you don't want to turn this off
           Of course only applies to AYIYA and heartbeat tunnels not to static ones
@@ -148,21 +142,18 @@ in {
       noConfigure = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Don't configure anything";
       };
 
       behindNAT = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Notify the user that a NAT-kind network is detected";
       };
 
       localIPv4Override = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Overrides the IPv4 parameter received from TIC
           This allows one to configure a NAT into "DMZ" mode and then

nixos/modules/services/networking/ferm.nix

@@ -19,7 +19,6 @@ in {
     services.ferm = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to enable Ferm Firewall.

nixos/modules/services/networking/firefox/sync-server.nix

@@ -33,7 +33,6 @@ in
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether to enable a Firefox Sync Server, this give the opportunity to
           Firefox users to store all synchronized data on their own server. To use this
@@ -78,7 +77,6 @@ in
       allowNewUsers = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = ''
           Whether to allow new-user signups on the server. Only request by
           existing accounts will be honored.

nixos/modules/services/networking/mosquitto.nix

@@ -147,7 +147,6 @@ in
 
       allowAnonymous = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Allow clients to connect without authentication.

nixos/modules/services/networking/quagga.nix

@@ -104,7 +104,6 @@ in
         enable = mkOption {
           type = types.bool;
           default = any isEnabled services;
-          example = true;
           description = ''
             Whether to enable the Zebra routing manager.
 

nixos/modules/services/networking/znc.nix

@@ -132,7 +132,6 @@ in
     services.znc = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Enable a ZNC service for a user.
@@ -251,7 +250,6 @@ in
 
         useSSL = mkOption {
           default = true;
-          example = true;
           type = types.bool;
           description = ''
             Indicates whether the ZNC server should use SSL when listening on the specified port. A self-signed certificate will be generated.
@@ -278,7 +276,6 @@ in
  
       mutable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Indicates whether to allow the contents of the `dataDir` directory to be changed

nixos/modules/services/scheduling/cron.nix

@@ -39,7 +39,7 @@ in
 
       enable = mkOption {
         type = types.bool;
-        example = true;
+        default = false;
         description = "Whether to enable the Vixie cron daemon.";
       };
 

nixos/modules/services/security/haka.nix

@@ -99,7 +99,6 @@ in
 
       pcap = mkOption {
         default = true;
-        example = false;
         type = types.bool;
         description = "Whether to enable pcap";
       };

nixos/modules/services/torrent/deluge.nix

@@ -13,7 +13,6 @@ in {
       deluge = {
         enable = mkOption {
           default = false;
-          example = true;
           description = "Start the Deluge daemon";
         };
 
@@ -29,7 +28,6 @@ in {
       deluge.web = {
         enable = mkOption {
           default = false;
-          example = true;
           description = ''
             Start Deluge Web daemon.
           '';

nixos/modules/services/web-apps/atlassian/crowd.nix

@@ -88,7 +88,6 @@ in
         secure = mkOption {
           type = types.bool;
           default = true;
-          example = false;
           description = "Whether the connections to the proxy should be considered secure.";
         };
       };

nixos/modules/services/web-apps/atlassian/jira.nix

@@ -78,7 +78,6 @@ in
         secure = mkOption {
           type = types.bool;
           default = true;
-          example = false;
           description = "Whether the connections to the proxy should be considered secure.";
         };
       };

nixos/modules/services/web-servers/caddy.nix

@@ -29,7 +29,6 @@ in
 
     agree = mkOption {
       default = false;
-      example = true;
       type = types.bool;
       description = "Agree to Let's Encrypt Subscriber Agreement";
     };

nixos/modules/services/x11/compton.nix

@@ -43,7 +43,6 @@ in {
     enable = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Whether of not to enable Compton as the X.org composite manager.
       '';
@@ -52,7 +51,6 @@ in {
     fade = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Fade windows in and out.
       '';
@@ -93,7 +91,6 @@ in {
     shadow = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Draw window shadows.
       '';

nixos/modules/services/x11/desktop-managers/enlightenment.nix

@@ -20,7 +20,6 @@ in
 
     services.xserver.desktopManager.enlightenment.enable = mkOption {
       default = false;
-      example = true;
       description = "Enable the Enlightenment desktop environment.";
     };
 

nixos/modules/services/x11/desktop-managers/gnome3.nix

@@ -53,7 +53,6 @@ in {
     services.xserver.desktopManager.gnome3 = {
       enable = mkOption {
         default = false;
-        example = true;
         description = "Enable Gnome 3 desktop manager.";
       };
 

nixos/modules/services/x11/desktop-managers/kodi.nix

@@ -11,7 +11,6 @@ in
     services.xserver.desktopManager.kodi = {
       enable = mkOption {
         default = false;
-        example = true;
         description = "Enable the kodi multimedia center.";
       };
     };

nixos/modules/services/x11/desktop-managers/xterm.nix

@@ -13,7 +13,6 @@ in
 
     services.xserver.desktopManager.xterm.enable = mkOption {
       default = true;
-      example = false;
       description = "Enable a xterm terminal as a desktop manager.";
     };
 

nixos/modules/services/x11/hardware/libinput.nix

@@ -73,7 +73,6 @@ in {
       clickMethod = mkOption {
         type = types.nullOr (types.enum [ "none" "buttonareas" "clickfinger" ]);
         default = null;
-        example = "none";
         description =
           ''
             Enables a click method. Permitted values are none, buttonareas, clickfinger.
@@ -85,14 +84,12 @@ in {
       leftHanded = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Enables left-handed button orientation, i.e. swapping left and right buttons.";
       };
 
       middleEmulation = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description =
           ''
             Enables middle button emulation. When enabled, pressing the left and right buttons
@@ -103,7 +100,6 @@ in {
       naturalScrolling = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Enables or disables natural scrolling behavior.";
       };
 
@@ -131,7 +127,6 @@ in {
       horizontalScrolling = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description =
           ''
             Disables horizontal scrolling. When disabled, this driver will discard any horizontal scroll
@@ -153,7 +148,6 @@ in {
       tapping = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description =
           ''
             Enables or disables tap-to-click behavior.
@@ -163,7 +157,6 @@ in {
       tappingDragLock = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description =
           ''
             Enables or disables drag lock during tapping behavior. When enabled, a finger up during tap-
@@ -175,7 +168,6 @@ in {
       disableWhileTyping = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description =
           ''
             Disable input method while typing.

nixos/modules/services/x11/hardware/multitouch.nix

@@ -18,20 +18,17 @@ in {
 
       enable = mkOption {
         default = false;
-        example = true;
         description = "Whether to enable multitouch touchpad support.";
       };
 
       invertScroll = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Whether to invert scrolling direction à la OSX Lion";
       };
 
       ignorePalm = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Whether to ignore touches detected as being the palm (i.e when typing)";
       };
@@ -39,7 +36,6 @@ in {
       tapButtons = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = "Whether to enable tap buttons.";
       };
 

nixos/modules/services/x11/hardware/synaptics.nix

@@ -29,7 +29,6 @@ in {
       enable = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Whether to enable touchpad support.";
       };
 
@@ -102,7 +101,6 @@ in {
       tapButtons = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = "Whether to enable tap buttons.";
       };
 
@@ -125,7 +123,6 @@ in {
       palmDetect = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = "Whether to enable palm detection (hardware support required)";
       };
 
@@ -146,7 +143,6 @@ in {
       horizontalScroll = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = "Whether to enable horizontal scrolling (on touchpad)";
       };
 

nixos/modules/services/x11/redshift.nix

@@ -12,7 +12,6 @@ in {
     enable = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         Enable Redshift to change your screen's colour temperature depending on
         the time of day.

nixos/modules/services/x11/unclutter-xfixes.nix

@@ -11,7 +11,6 @@ in {
       description = "Enable unclutter-xfixes to hide your mouse cursor when inactive.";
       type = types.bool;
       default = false;
-      example = true;
     };
 
     package = mkOption {

nixos/modules/services/x11/unclutter.nix

@@ -11,7 +11,6 @@ in {
       description = "Enable unclutter to hide your mouse cursor when inactive";
       type = types.bool;
       default = false;
-      example = true;
     };
 
     package = mkOption {

nixos/modules/services/x11/urxvtd.nix

@@ -11,7 +11,6 @@ in {
   options.services.urxvtd.enable = mkOption {
     type = types.bool;
     default = false;
-    example = true;
     description = ''
       Enable urxvtd, the urxvt terminal daemon. To use urxvtd, run
       "urxvtc".

nixos/modules/services/x11/window-managers/exwm.nix

@@ -21,7 +21,6 @@ in
       enable = mkEnableOption "exwm";
       enableDefaultConfig = mkOption {
         default = true;
-        example = false;
         type = lib.types.bool;
         description = "Enable an uncustomised exwm configuration.";
       };

nixos/modules/services/x11/window-managers/xmonad.nix

@@ -44,7 +44,6 @@ in
 
       enableContribAndExtras = mkOption {
         default = false;
-        example = true;
         type = lib.types.bool;
         description = "Enable xmonad-{contrib,extras} in Xmonad.";
       };

nixos/modules/system/boot/loader/grub/grub.nix

@@ -381,7 +381,6 @@ in
 
       efiInstallAsRemovable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to invoke <literal>grub-install</literal> with

nixos/modules/tasks/filesystems/zfs.nix

@@ -109,7 +109,6 @@ in
       forceImportRoot = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = ''
           Forcibly import the ZFS root pool(s) during early boot.
 
@@ -128,7 +127,6 @@ in
       forceImportAll = mkOption {
         type = types.bool;
         default = true;
-        example = false;
         description = ''
           Forcibly import all ZFS pool(s).
 

nixos/modules/tasks/network-interfaces.nix

@@ -548,7 +548,6 @@ in
           };
 
           rstp = mkOption {
-            example = true;
             default = false;
             type = types.bool;
             description = "Whether the bridge interface should enable rstp.";

nixos/modules/virtualisation/containers.nix

@@ -274,7 +274,6 @@ let
       };
       isReadOnly = mkOption {
         default = true;
-        example = true;
         type = types.bool;
         description = "Determine whether the mounted path will be accessed in read-only mode.";
       };