Issue with caching when views outside of dbt schemas select from dbt-managed schemas

[drewbanin]

Issue

Issue description

dbt's caching will fail hard on PG/Redshift if there exists a view outside of a dbt-controlled schema that depends on a relation inside of a dbt controlled schema.

Results

InternalException: Cache inconsistency detected: in add_link, dependent link key _ReferenceKey(schema=u'dbt_airflow_events', identifier=u'tracking_l30d') not in cache!

System information

The output of dbt --version:

0.12.0

Steps to reproduce

1. Create and run an example model

-- models/test_it.sql

select 1 as id

2. Run the model

dbt run

3. Create an external dependency on this model

create schema debug;
create view debug.debug as (
  select * from analytics.test_it -- the model created above
)

4. Run dbt again

# this will fail
dbt run