title: How is it possible to get "ActiveRecord::DuplicateMigrationNameError" with only 1 migration file?
body: <p>Here is the setup.  Have a Ruby off Rails API application setup.  </p>
  
  <p>It pulls in a "database creation application" independently via git submodule.  There is a "db/migrate" folder with one migration file and a "db/structure.sql" file.  The database creation project is essentially a slimmed down Rails project - we used Rails because we needed rake tasks to let us easily migrate.</p>
  
  <p>The structure.sql file essentially recreates our old database schema (we decided to keep the database code in a separate repo due to having multiple apps that need to access the database and a desire to keep the database consistent as possible).</p>
  
  <p>If I do <code>rake db:create</code> I get told that <code>app_development</code> and <code>app_test</code> exist.  I've manually deleted the schema_migrations and schema_info tables from both. In fact app_test, is empty and contains no tables.</p>
  
  <p>If I run rake db:migrate, I get told:</p>
  
  <pre><code>ActiveRecord::DuplicateMigrationNameError: 
  
  Multiple migrations have the name YourMigrationToTableBlahBlah
  </code></pre>
  
  <p>How is this possible and how do I work around this error so I can migrate?</p>
  
  <p>At one point I did do a git commit that renamed the columns in the 1 migration file in db/migration, but I deleted the tables in app_development and app_test as well as the schema_migrations table so the Rails rake task should not be complaining about this.</p>
  
  <p>EDIT:</p>
  
  <p>One thing I noticed is that during the running of <code>bundle exec rake db:migrate</code> is that the same migrations folder path (e.g., "db/migrate") is being added to <code>ActiveRecord::Tasks::DatabaseTasks.migrations_paths</code> but I don't know why </p>