Heroku migration: type modifier is not allowed for type "bytea"

ruby-on-rails ruby-on-rails-3 postgresql migration heroku

From Heroku's docs:

Binary field limit

Cause: PostgreSQL doesn’t limit binary fields. Any migrations adding a :binary field with the :limit option will raise a syntax error.

Solution: Omit the :limit for binary fields if possible — or test the DB before running it.