swayidle: make -w optional

The option -w causes swayidle to wait on timeouts/events to finish.
This can cause problems with certain timout/event commands (see
https://github.com/swaywm/swaylock/issues/86#issuecomment-662702180)

docs/release-notes/rl-2411.md

@@ -7,7 +7,16 @@ is therefore not final.
 
 This release has the following notable changes:
 
-- No changes.
+- The swayidle module behavior has changed. Specifically, swayidle was
+  previously always called with a `-w` flag. This flag is now moved to
+  the default
+  [services.swayidle.extraArgs](#opt-services.swayidle.extraArgs)
+  value to make it optional.
+
+  Your configuration may break if you already set this option and also
+  rely on the flag being automatically added. To resolve this, please
+  add `-w` to your assignment of
+  [services.swayidle.extraArgs](#opt-services.swayidle.extraArgs).
 
 ## State Version Changes {#sec-release-24.11-state-version-changes}
 

modules/misc/news.nix

@@ -1734,6 +1734,20 @@ in {
           list of themes.
         '';
       }
+
+      {
+        time = "2024-09-20T07:48:08+00:00";
+        condition = hostPlatform.isLinux && config.services.swayidle.enable;
+        message = ''
+          The swayidle module behavior has changed. Specifically, swayidle was
+          previously always called with a `-w` flag. This flag is now moved to
+          the default `services.swayidle.extraArgs` value to make it optional.
+
+          Your configuration may break if you already set this option and also
+          rely on the flag being automatically added. To resolve this, please
+          add `-w` to your assignment of `services.swayidle.extraArgs`.
+        '';
+      }
     ];
   };
 }

modules/services/swayidle.nix

@@ -94,7 +94,7 @@ in {
 
     extraArgs = mkOption {
       type = with types; listOf str;
-      default = [ ];
+      default = [ "-w" ];
       description = "Extra arguments to pass to swayidle.";
     };
 
@@ -127,8 +127,7 @@ in {
         Restart = "always";
         # swayidle executes commands using "sh -c", so the PATH needs to contain a shell.
         Environment = [ "PATH=${makeBinPath [ pkgs.bash ]}" ];
-        ExecStart =
+        ExecStart = "${cfg.package}/bin/swayidle ${concatStringsSep " " args}";
-          "${cfg.package}/bin/swayidle -w ${concatStringsSep " " args}";
       };
 
       Install = { WantedBy = [ cfg.systemdTarget ]; };