https://github.com/sqlalchemy/sqlalchemy/commit/3cd9a5b42f850618141ec459cffe30d0ade0f191 changed the signature of the _make_proxy method which we're using in https://github.com/agdsn/pycroft/blob/6de9a64d8ba4e6b0392f81e2469a7444c75209af/pycroft/model/ddl.py#L437