Flask-migrate: No changes in schema detected.

[VChertukhin]

First migrations were quite ok, but I've just added a new table and executed
flask db migrate
which responded me with
INFO [alembic.runtime.migration] Context impl PostgresqlImpl. INFO [alembic.runtime.migration] Will assume transactional DDL. INFO [alembic.env] No changes in schema detected.
I would be grateful if you could help me to deal with this problem.

[miguelgrinberg]

Did you import your new model? If yes, did you make sure your database does not have the new table when you generated the migration?

[VChertukhin]

Good afternoon, Miguel! I did import my model and there was no table after migration. Anyway when I reinstalled my virtual environment (and deleted migrations folder as well) everything wen quite well then.