An exception message with None as an error message is not really useful. Since DbMigrationError is also wrongly written with a lower case b whereas everything else has a major B, let's create a new correct class and use it. debtcollector is used to deprecate the old one, and inheritance makes sure the current code works. Change-Id: Id9a477aff38afd5b664b75a549ad561f4c24b6f0
This module could be used either for: 1. Smooth transition from migrate tool to alembic 2. As standalone alembic tool
Core points: 1. Upgrade/downgrade database with usage of alembic/migrate migrations or both 2. Compatibility with oslo.config 3. The way to autogenerate new revisions or stamps