Revert "Revert "ibus: fix dconf db installation""

This reverts commit ee5cba24c31896b6aeb0af4e21b93b878e54f747.

nixos/tests/installed-tests/ibus.nix

@@ -5,16 +5,12 @@ makeInstalledTest {
 
   testConfig = {
     i18n.inputMethod.enabled = "ibus";
+    systemd.user.services.ibus-daemon = {
+      serviceConfig.ExecStart = "${pkgs.ibus}/bin/ibus-daemon --xim --verbose";
+      wantedBy = [ "graphical-session.target" ];
+      partOf = [ "graphical-session.target" ];
+    };
   };
 
-  preTestScript = ''
-    # ibus has ibus-desktop-testing-runner but it tries to manage desktop session so we just spawn ibus-daemon ourselves
-    machine.succeed("ibus-daemon --daemonize --verbose")
-  '';
-
   withX11 = true;
-
-  # TODO: ibus-daemon is currently crashing or something
-  # maybe make ibus systemd service that auto-restarts?
-  meta.broken = true;
 }

pkgs/tools/inputmethods/ibus/default.nix

@@ -16,6 +16,7 @@
 , gtk2
 , gtk3
 , gtk-doc
+, runCommand
 , isocodes
 , cldr-emoji-annotation
 , unicode-character-database
@@ -47,6 +48,14 @@ let
       makeWrapper ${glib.dev}/bin/glib-mkenums $out/bin/glib-mkenums --unset PYTHONPATH
     '';
   };
+  # make-dconf-override-db.sh needs to execute dbus-launch in the sandbox,
+  # it will fail to read /etc/dbus-1/session.conf unless we add this flag
+  dbus-launch = runCommand "sandbox-dbus-launch" {
+    nativeBuildInputs = [ makeWrapper ];
+  } ''
+      makeWrapper ${dbus}/bin/dbus-launch $out/bin/dbus-launch \
+        --add-flags --config-file=${dbus.daemon}/share/dbus-1/session.conf
+  '';
 in
 
 stdenv.mkDerivation rec {
@@ -71,7 +80,7 @@ stdenv.mkDerivation rec {
   outputs = [ "out" "dev" "installedTests" ];
 
   postPatch = ''
-    echo \#!${runtimeShell} > data/dconf/make-dconf-override-db.sh
+    patchShebangs --build data/dconf/make-dconf-override-db.sh
     cp ${buildPackages.gtk-doc}/share/gtk-doc/data/gtk-doc.make .
   '';
 
@@ -105,6 +114,7 @@ stdenv.mkDerivation rec {
     python3BuildEnv
     vala
     wrapGAppsHook
+    dbus-launch
   ];
 
   propagatedBuildInputs = [