use full manifest in adapter instead of macro_manifest (#10609)

* use full manifest in adapter instead of macro_manifest

* Add test case

* Add changelog entry

* Remove commented code.

---------

Co-authored-by: Peter Allen Webb <peter.webb@dbtlabs.com>

.changes/unreleased/Fixes-20240829-105701.yaml

@@ -0,0 +1,7 @@
+kind: Fixes
+body: Allow the use of env_var function in certain macros in which it was previously
+  unavailable.
+time: 2024-08-29T10:57:01.160613-04:00
+custom:
+  Author: peterallenwebb
+  Issue: "10609"

core/dbt/parser/manifest.py

@@ -1028,12 +1028,11 @@ def build_manifest_state_check(self):
         return state_check
 
     def save_macros_to_adapter(self, adapter):
-        macro_manifest = MacroManifest(self.manifest.macros)
-        adapter.set_macro_resolver(macro_manifest)
+        adapter.set_macro_resolver(self.manifest)
         # This executes the callable macro_hook and sets the
         # query headers
         # This executes the callable macro_hook and sets the query headers
-        query_header_context = generate_query_header_context(adapter.config, macro_manifest)
+        query_header_context = generate_query_header_context(adapter.config, self.manifest)
         self.macro_hook(query_header_context)
 
     # This creates a MacroManifest which contains the macros in

tests/functional/context_methods/test_env_vars.py

@@ -193,3 +193,36 @@ def test_env_vars_secrets(self, project):
         assert not ("secret_variable" in log_output)
         assert "regular_variable" in log_output
         del os.environ["DBT_DEBUG"]
+
+
+class TestEnvVarInCreateSchema:
+    """Test that the env_var() method works in overrides of the create_schema
+    macro, which is called during a different phase of execution than most
+    macros, causing problems."""
+
+    @pytest.fixture(scope="class", autouse=True)
+    def setup(self):
+        os.environ["DBT_TEST_ENV_VAR"] = "1"
+
+    @pytest.fixture(scope="class")
+    def macros(self):
+        return {
+            "macros.sql": """
+                {% macro create_schema(relation) %}
+                  {%- call statement('create_schema') -%}
+                     SELECT {{ env_var('DBT_TEST_ENV_VAR') }} as TEST
+                  {% endcall %}
+                {% endmacro %}%
+            """
+        }
+
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "mymodel.sql": """
+            SELECT 1 as TEST -- {%- do adapter.create_schema(this) -%}
+        """
+        }
+
+    def test_env_var_in_create_schema(self, project):
+        run_dbt(["run"])