title: Why alembic didn't generate migration?
body: <p>When I run command</p>
  
  <pre><code>alembic revision --autogenerate -m "Reconciliation and daily amount tables"
  </code></pre>
  
  <p>It gives me output:</p>
  
  <pre><code>INFO  [alembic.runtime.migration] Context impl PostgresqlImpl.
  INFO  [alembic.runtime.migration] Will assume transactional DDL.
  ERROR [alembic.util.messaging] Can't locate revision identified by '67ad9835cada'
    FAILED: Can't locate revision identified by '67ad9835cada'
  </code></pre>
  
  <p>What is the source for the problem?</p>