Ecto.Adapter.Transaction.rollback

You're seeing just the callback rollback, go back to Ecto.Adapter.Transaction module for more information.
Link to this callback

rollback(adapter_meta, value)

View Source

Specs

rollback(adapter_meta(), value :: any()) :: no_return()

Rolls back the current transaction.

The transaction will return the value given as {:error, value}.

See Ecto.Repo.rollback/1.