[gnome-font-viewer] font-model: add some debug information

[Cosimo Cecchi <cosimoc src gnome org>]

commit 2b72eab3d03f0673538b7c34941dc96e5e09dde7
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Thu Jul 4 14:20:34 2019 -0700

    font-model: add some debug information

 src/font-model.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/src/font-model.c b/src/font-model.c
index 8301f45..bd6d266 100644
--- a/src/font-model.c
+++ b/src/font-model.c
@@ -186,19 +186,24 @@ create_thumbnail (ThumbInfoData *thumb_info)
     GFile *file = thumb_info->font_file;
     GnomeDesktopThumbnailFactory *factory;
     guint64 mtime;
+    GError *error = NULL;
 
     GdkPixbuf *pixbuf = NULL;
     GFileInfo *info = NULL;
 
     info = g_file_query_info (file, ATTRIBUTES_FOR_CREATING_THUMBNAIL,
                               G_FILE_QUERY_INFO_NONE,
-                              NULL, NULL);
+                              NULL, &error);
 
     /* we don't care about reporting errors here, just fail the
      * thumbnail.
      */
-    if (info == NULL)
+    if (info == NULL) {
+        char *font_path = g_file_get_path (file);
+        g_debug ("Can't query info for file %s: %s\n", font_path, error->message);
+        g_free (font_path);
         goto out;
+    }
 
     mtime = g_file_info_get_attribute_uint64 (info, G_FILE_ATTRIBUTE_TIME_MODIFIED);
 
@@ -217,6 +222,7 @@ create_thumbnail (ThumbInfoData *thumb_info)
   g_object_unref (factory);
 
  out:
+  g_clear_error (&error);
   g_clear_object (&info);
 
   if (pixbuf != NULL)