Partial parsing: duplicate resource error

[drewbanin]

Describe the bug

When the --partial-parse flag is enable, dbt can fail with an errant compilation error:

$ dbt --partial-parse compile
Running with dbt=0.15.0
Encountered an error:
Compilation Error
  dbt found two resources with the name "adwords_ad_performance_adapter". Since these resources have the same name,
  dbt will be unable to find the correct resource when ref("adwords_ad_performance_adapter") is used. To fix this,
  change the name of one of these resources:
  - model.adwords.adwords_ad_performance_adapter (models/router/adapter/criteria/adwords_ad_performance_adapter.sql)
  - model.adwords.adwords_ad_performance_adapter (models/router/adapter/criteria/adwords_ad_performance_adapter.sql)

dbt is reporting the same model twice. Interestingly, there actually are two instances of models named adwords_ad_performance_adapter in the adwords package:

• https://github.com/fishtown-analytics/adwords/blob/master/models/router/adapter/criteria/adwords_ad_performance_adapter.sql
• https://github.com/fishtown-analytics/adwords/blob/master/models/router/adapter/url/adwords_ad_performance_adapter.sql

These models are conditionally enabled using a variable, adapter_value, defined in the dbt_project.yml file.

It's not yet clear to me if dbt is failing because it's finding both of these models and reporting an errant error message, or if dbt really is picking up the same model twice somehow.

Steps To Reproduce

Add the following to packages.yml:

packages:
  - package: fishtown-analytics/adwords
    version: 0.2.9

Add the following to dbt_project.yml:

models:
    adwords:
        vars:
            adapter_value: criteria

Create a model called adwords_criteria_performance.sql with the contents:

select 1 as id

# Succeeds
$ dbt compile

# Fails with duplicate model error
$ dbt --partial-parse compile

Expected behavior

dbt should compile and run this project successfully.

The output of dbt --version:

dbt v0.15.0

[drewbanin]

fixed in #2056