Gtk Error when plotting w/ FreeBSD

[hasandiwan]

My Flask application started giving me this error:

 Gtk-CRITICAL **: 08:00:01.308: _gtk_css_lookup_resolve: assertion '(((__extension__ ({ GTypeInstance *__inst = (GTypeInstance*) ((provider)); GType __t = ((_gtk_style_provider_private_get_type ())); gboolean __r; if (!__inst) __r = (0); else if (__inst->g_class && __inst->g_class->g_type == __t) __r = (!(0)); else __r = g_type_check_instance_is_a (__inst, __t); __r; }))))' failed

(gunicorn:18903): Gtk-ERROR **: 08:00:01.308: Can't create a GtkStyleContext without a display connection

[has2k1]

I cannot connect this to plotnine.