[gnome-photos/uajain/tracker-not-found-error] tracker: Be more informative about tracker not found error string

[Umang Jain <uajain src gnome org>]

commit 82c29b2c677250be74aaa165899a77a2b62167b3
Author: Umang Jain <umang endlessm com>
Date:   Wed Dec 5 15:36:47 2018 +0530

    tracker: Be more informative about tracker not found error string

 src/photos-tracker-controller.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/src/photos-tracker-controller.c b/src/photos-tracker-controller.c
index b0476e7f..8b6c759c 100644
--- a/src/photos-tracker-controller.c
+++ b/src/photos-tracker-controller.c
@@ -165,10 +165,14 @@ photos_tracker_controller_item_added_removed (PhotosTrackerController *self)
 static void
 photos_tracker_controller_query_error (PhotosTrackerController *self, GError *error)
 {
-  const gchar *primary = _("Unable to fetch the list of photos");
+  const gchar *primary;
 
   if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
     return;
+  else if (g_error_matches (error, G_DBUS_ERROR, G_DBUS_ERROR_SERVICE_UNKNOWN))
+    primary = _("Missing Tracker on host, please install Tracker");
+  else
+    primary = _("Unable to fetch the list of photos");
 
   g_signal_emit (self, signals[QUERY_ERROR], 0, primary, error->message);
 }