Merge pull request #100141 from xaverdh/xmonad-correct-path

xmonad: put the correct xmonad binary in PATH

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

@@ -4,13 +4,15 @@ with lib;
 let
   inherit (lib) mkOption mkIf optionals literalExample;
   cfg = config.services.xserver.windowManager.xmonad;
-  xmonad = pkgs.xmonad-with-packages.override {
+
+  xmonad-vanilla = pkgs.xmonad-with-packages.override {
     ghcWithPackages = cfg.haskellPackages.ghcWithPackages;
     packages = self: cfg.extraPackages self ++
                      optionals cfg.enableContribAndExtras
                      [ self.xmonad-contrib self.xmonad-extras ];
   };
-  xmonadBin = pkgs.writers.writeHaskell "xmonad" {
+
+  xmonad-config = pkgs.writers.writeHaskellBin "xmonad" {
     ghc = cfg.haskellPackages.ghc;
     libraries = [ cfg.haskellPackages.xmonad ] ++
                 cfg.extraPackages cfg.haskellPackages ++
@@ -19,8 +21,10 @@ let
     inherit (cfg) ghcArgs;
   } cfg.config;
 
-in
-{
+  xmonad = if (cfg.config != null) then xmonad-config else xmonad-vanilla;
+in {
+  meta.maintainers = with maintainers; [ lassulus xaverdh ];
+
   options = {
     services.xserver.windowManager.xmonad = {
       enable = mkEnableOption "xmonad";
@@ -62,19 +66,50 @@ in
         default = null;
         type = with lib.types; nullOr (either path str);
         description = ''
-          Configuration from which XMonad gets compiled. If no value
-          is specified, the xmonad config from $HOME/.xmonad is taken.
-          If you use xmonad --recompile, $HOME/.xmonad will be taken as
-          the configuration, but on the next restart of display-manager
-          this config will be reapplied.
+          Configuration from which XMonad gets compiled. If no value is
+          specified, a vanilla xmonad binary is put in PATH, which will
+          attempt to recompile and exec your xmonad config from $HOME/.xmonad.
+          This setup is then analogous to other (non-NixOS) linux distributions.
+
+          If you do set this option, you likely want to use "launch" as your
+          entry point for xmonad (as in the example), to avoid xmonads
+          recompilation logic on startup. Doing so will render the default
+          "mod+q" restart key binding dysfunctional though, because that attempts
+          to call your binary with the "--restart" command line option, unless
+          you implement that yourself. You way mant to bind "mod+q" to
+          <literal>(restart "xmonad" True)</literal> instead, which will just restart
+          xmonad from PATH. This allows e.g. switching to the new xmonad binary,
+          after rebuilding your system with nixos-rebuild.
+
+          If you actually want to run xmonad with a config specified here, but
+          also be able to recompile and restart it from a copy of that source in
+          $HOME/.xmonad on the fly, you will have to implement that yourself
+          using something like "compileRestart" from the example.
+          This should allow you to switch at will between the local xmonad and
+          the one NixOS puts in your PATH.
         '';
         example = ''
           import XMonad
+          import XMonad.Util.EZConfig (additionalKeys)
+          import Text.Printf (printf)
+          import System.Posix.Process (executeFile)
+          import System.Info (arch,os)
+          import System.Environment (getArgs)
+          import System.FilePath ((</>))
+
+          compiledConfig = printf "xmonad-%s-%s" arch os
+
+          compileRestart = whenX (recompile True) . catchIO $ do
+              dir  <- getXMonadDataDir
+              args <- getArgs
+              executeFile (dir </> compiledConfig) False args Nothing
 
           main = launch defaultConfig
               { modMask = mod4Mask -- Use Super instead of Alt
-                 , terminal = "urxvt"
-                 }
+              , terminal = "urxvt" }
+              `additionalKeys`
+              [ ( (mod4Mask,xK_r), compileRestart )
+              , ( (mod4Mask,xK_q), restart "xmonad" True ) ]
         '';
       };
 
@@ -101,10 +136,8 @@ in
     services.xserver.windowManager = {
       session = [{
         name = "xmonad";
-        start = let
-          xmonadCommand = if (cfg.config != null) then xmonadBin else "${xmonad}/bin/xmonad";
-        in ''
-           systemd-cat -t xmonad -- ${xmonadCommand} ${lib.escapeShellArgs cfg.xmonadCliArgs} &
+        start = ''
+           systemd-cat -t xmonad -- ${xmonad}/bin/xmonad ${lib.escapeShellArgs cfg.xmonadCliArgs} &
            waitPID=$!
         '';
       }];

nixos/tests/xmonad.nix

@@ -14,9 +14,16 @@ import ./make-test-python.nix ({ pkgs, ...} : {
       extraPackages = with pkgs.haskellPackages; haskellPackages: [ xmobar ];
       config = ''
         import XMonad
+        import XMonad.Operations (restart)
         import XMonad.Util.EZConfig
-        main = launch $ def `additionalKeysP` myKeys
-        myKeys = [ ("M-C-x", spawn "xterm") ]
+        import XMonad.Util.SessionStart
+
+        main = launch $ def { startupHook = startup } `additionalKeysP` myKeys
+
+        startup = isSessionStart >>= \sessInit ->
+          if sessInit then setSessionStarted else spawn "xterm"
+
+        myKeys = [ ("M-C-x", spawn "xterm"), ("M-q", restart "xmonad" True) ]
       '';
     };
   };
@@ -30,12 +37,11 @@ import ./make-test-python.nix ({ pkgs, ...} : {
     machine.send_key("alt-ctrl-x")
     machine.wait_for_window("${user.name}.*machine")
     machine.sleep(1)
-    machine.screenshot("terminal")
-    machine.wait_until_succeeds("xmonad --restart")
+    machine.screenshot("terminal1")
+    machine.send_key("alt-q")
     machine.sleep(3)
-    machine.send_key("alt-shift-ret")
     machine.wait_for_window("${user.name}.*machine")
     machine.sleep(1)
-    machine.screenshot("terminal")
+    machine.screenshot("terminal2")
   '';
 })