After upgrading from Rails 3 to Rails 4 the db:schema:load task is failing. I did some digging into it and found that after the upgrade when I run bundle exec rake db:schema:load the db/schema.rb file is being loaded twice. The first time it runs fine; then the second time through it fails due to a create_table force: true fails due to there being a dependency constraint on the table.
I've stripped out every additional rake task and enhance to try and rule out any of my code, but still this loads the schema.rb twice. It is always exactly twice as I am able to run it successfully on SQLite and see the same behavior there, but it runs to completion due to SQLite not enforcing the table constraints.