Mimics Django's error handler but adds ``STATIC_URL`` to the
    context.

def server_error(request, template_name="errors/500.html"):
    """
    Mimics Django's error handler but adds ``STATIC_URL`` to the
    context.
    """
    context = {"STATIC_URL": settings.STATIC_URL}
    t = get_template(template_name)
    return HttpResponseServerError(t.render(context, request))