Otherwise, t/overrides.t and t/zz-GtkRecentChooserDialog.t fail in a Debian
sbuild build environment, with errors such as:

  Gtk-CRITICAL **: Unable to create user data directory  '/sbuild-nonexistent/.local/share' for storing the recently used files list:  Permission denied  **  Gtk:ERROR:/tmp/buildd/gtk+3.0-3.8.4/./gtk/gtkrecentmanager.c:622:gtk_recent_manager_set_filename:  assertion failed: (priv->filename != NULL)