remove Compilation Error messages

core/dbt/clients/yaml_helper.py

@@ -31,11 +31,13 @@ class UniqueKeyLoader(SafeLoader):
 
     def construct_mapping(self, node, deep=False):
         mapping = set()
+        self.flatten_mapping(node)  # This processes yaml anchors / merge keys (<<).
         for key_node, value_node in node.value:
             key = self.construct_object(key_node, deep=deep)
             if key in mapping:
-                raise dbt.exceptions.DuplicateYamlKeyException(
-                    f"Duplicate {key!r} key found in yaml file"
+                msg = f"Duplicate {key!r} key found in yaml file"
+                dbt.exceptions.warn_or_raise(
+                    dbt.exceptions.DuplicateYamlKeyException(msg), log_fmt=warning_tag("{}")
                 )
             mapping.add(key)
         return super().construct_mapping(node, deep)
@@ -82,7 +84,3 @@ def load_yaml_text(contents, path=None):
             error = str(e)
 
         raise dbt.exceptions.ValidationException(error)
-    except dbt.exceptions.DuplicateYamlKeyException as e:
-        # TODO: We may want to raise an exception instead of a warning in the future.
-        e.msg = f"{e} {path.searched_path}/{path.relative_path}."
-        dbt.exceptions.warn_or_raise(e, log_fmt=warning_tag("{}"))

core/dbt/exceptions.py

@@ -438,7 +438,8 @@ class InvalidSelectorException(RuntimeException):
 
 
 class DuplicateYamlKeyException(CompilationException):
-    pass
+    def __str__(self):
+        return self.msg
 
 
 def raise_compiler_error(msg, node=None) -> NoReturn:

test/unit/test_yaml_loader.py

@@ -0,0 +1,28 @@
+from dbt.clients.yaml_helper import load_yaml_text
+import unittest
+
+profile_with_anchor = """
+# profiles.yml
+
+postgres:
+  outputs:
+    dev: &profile
+      type: postgres
+      host: localhost
+      user: root
+      password: password
+      schema: public
+      database: postgres
+      port: 5432
+      threads: 8
+    prod:
+      <<: *profile
+    uat: *profile
+  target: dev
+"""
+
+class YamlLoadingUnitTest(unittest.TestCase):
+
+    def test_load_yaml_anchors(self):
+        profile_yml = load_yaml_text(profile_with_anchor)
+        assert(profile_yml)

tests/functional/duplications/test_basic_duplications.py

@@ -2,6 +2,7 @@ import pytest
 
 from dbt.tests.util import run_dbt_and_capture, run_dbt
 from dbt.exceptions import DuplicateYamlKeyException
+from dbt.clients.yaml_helper import load_yaml_text
 
 duplicate_key_schema__schema_yml = """
 version: 2
@@ -15,6 +16,18 @@ my_model_sql = """
   select 1 as fun
 """
 
+duplicate_vars__dbt_project_yml = """
+# dbt_project.yml
+
+vars:
+  foo: bar
+  foo: bar
+"""
+
+my_model_vars_sql = """
+  select '{{ var("foo") }}' as val
+"""
+
 
 class TestBasicDuplications:
     @pytest.fixture(scope="class")
@@ -26,8 +39,21 @@ class TestBasicDuplications:
 
     def test_warning_in_stdout(self, project):
         results, stdout = run_dbt_and_capture(["run"])
-        assert "Duplicate 'models' key found in yaml file models/schema.yml" in stdout
+        assert "Duplicate 'models' key found in yaml" in stdout
 
     def test_exception_is_raised_with_warn_error_flag(self, project):
         with pytest.raises(DuplicateYamlKeyException):
             run_dbt(["--warn-error", "run"])
+
+
+class TestVarsDuplications:
+    @pytest.fixture(scope="class")
+    def project_config_update(self):
+        return load_yaml_text(duplicate_vars__dbt_project_yml)
+
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {"my_model_vars.sql": my_model_vars_sql}
+
+    def test_duplicate_vars_suceeds(self, project):
+        run_dbt(["run"])