and it dies with:
RAILS_ENV=production rake db:migrate
Then, first try using the --trace option:
(in /path/to/some/project) rake aborted! ORA-04043: object plural_name_of_a_model does not exist /path/to/some/project/Rakefile:10 (See full trace by running task with --trace)
If the error is coming from a controller, move that controller and any others that fail to the base project directory (or somewhere outside of where it is supposed to be) and then run the migration again. Be sure to move the controllers back afterwards.
RAILS_ENV=production rake db:migrate --trace