nixos/lightdm-gtk-greeter: don't wrap in module

nixos/modules/services/x11/display-managers/lightdm-greeters/gtk.nix

@@ -15,34 +15,6 @@ let
   icons = cfg.iconTheme.package;
   cursors = cfg.cursorTheme.package;
 
-  # The default greeter provided with this expression is the GTK greeter.
-  # Again, we need a few things in the environment for the greeter to run with
-  # fonts/icons.
-  wrappedGtkGreeter = pkgs.runCommand "lightdm-gtk-greeter" {
-      buildInputs = [ pkgs.makeWrapper ];
-      preferLocalBuild = true;
-    } ''
-      # This wrapper ensures that we actually get themes
-      makeWrapper ${pkgs.lightdm_gtk_greeter}/sbin/lightdm-gtk-greeter \
-        $out/greeter \
-        --prefix PATH : "${lib.getBin pkgs.stdenv.cc.libc}/bin" \
-        --set GDK_PIXBUF_MODULE_FILE "${pkgs.librsvg.out}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache" \
-        --set GTK_PATH "${theme}:${pkgs.gtk3.out}" \
-        --set GTK_EXE_PREFIX "${theme}" \
-        --set GTK_DATA_PREFIX "${theme}" \
-        --set XDG_DATA_DIRS "${theme}/share:${icons}/share" \
-        --set XDG_CONFIG_HOME "${theme}/share" \
-        --set XCURSOR_PATH "${cursors}/share/icons"
-
-      cat - > $out/lightdm-gtk-greeter.desktop << EOF
-      [Desktop Entry]
-      Name=LightDM Greeter
-      Comment=This runs the LightDM Greeter
-      Exec=$out/greeter
-      Type=Application
-      EOF
-    '';
-
   gtkGreeterConf = writeText "lightdm-gtk-greeter.conf"
     ''
     [greeter]
@@ -185,10 +157,16 @@ in
   config = mkIf (ldmcfg.enable && cfg.enable) {
 
     services.xserver.displayManager.lightdm.greeter = mkDefault {
-      package = wrappedGtkGreeter;
+      package = pkgs.lightdm_gtk_greeter.xgreeters;
       name = "lightdm-gtk-greeter";
     };
 
+    environment.systemPackages = [
+      cursors
+      icons
+      theme
+    ];
+
     environment.etc."lightdm/lightdm-gtk-greeter.conf".source = gtkGreeterConf;
 
   };

pkgs/applications/display-managers/lightdm/gtk-greeter.nix

@@ -1,7 +1,18 @@
-{ stdenv, fetchurl, lightdm, pkgconfig, intltool
+{ stdenv
-, hicolor-icon-theme, makeWrapper
+, lightdm_gtk_greeter
-, useGTK2 ? false, gtk2, gtk3 # gtk3 seems better supported
+, fetchurl
-, exo, at-spi2-core
+, lightdm
+, pkgconfig
+, intltool
+, linkFarm
+, wrapGAppsHook
+, useGTK2 ? false
+, gtk2
+, gtk3 # gtk3 seems better supported
+, exo
+, at-spi2-core
+, librsvg
+, hicolor-icon-theme
 }:
 
 #ToDo: bad icons with gtk2;
@@ -20,14 +31,15 @@ stdenv.mkDerivation rec {
     sha256 = "1pis5qyg95pg31dvnfqq34bzgj00hg4vs547r8h60lxjk81z8p15";
   };
 
-  nativeBuildInputs = [ pkgconfig ];
+  nativeBuildInputs = [ pkgconfig intltool wrapGAppsHook ];
-  buildInputs = [ lightdm exo intltool makeWrapper hicolor-icon-theme ]
+  buildInputs = [ lightdm exo librsvg hicolor-icon-theme ]
     ++ (if useGTK2 then [ gtk2 ] else [ gtk3 ]);
 
   configureFlags = [
     "--localstatedir=/var"
     "--sysconfdir=/etc"
     "--disable-indicator-services-command"
+    "--sbindir=${placeholder "out"}/bin" # for wrapGAppsHook to wrap automatically
   ] ++ stdenv.lib.optional useGTK2 "--with-gtk2";
 
   preConfigure = ''
@@ -44,10 +56,13 @@ stdenv.mkDerivation rec {
   postInstall = ''
     substituteInPlace "$out/share/xgreeters/lightdm-gtk-greeter.desktop" \
       --replace "Exec=lightdm-gtk-greeter" "Exec=$out/sbin/lightdm-gtk-greeter"
-    wrapProgram "$out/sbin/lightdm-gtk-greeter" \
-      --prefix XDG_DATA_DIRS ":" "${hicolor-icon-theme}/share"
   '';
 
+  passthru.xgreeters = linkFarm "lightdm-gtk-greeter-xgreeters" [{
+    path = "${lightdm_gtk_greeter}/share/xgreeters/lightdm-gtk-greeter.desktop";
+    name = "lightdm-gtk-greeter.desktop";
+  }];
+
   meta = with stdenv.lib; {
     homepage = https://launchpad.net/lightdm-gtk-greeter;
     platforms = platforms.linux;