Try out this hack

dbt/adapters/duckdb/impl.py

@@ -237,8 +237,17 @@ def render_column_constraint(cls, constraint: ColumnLevelConstraint) -> Optional
         """Render the given constraint as DDL text. Should be overriden by adapters which need custom constraint
         rendering."""
         if constraint.type == ConstraintType.foreign_key:
-            # DuckDB doesn't support 'foreign key' as an alias
-            return f"references {constraint.expression}"
+            if constraint.to and constraint.to_columns:
+                # TODO: this is a hack to get around a limitation in DuckDB around setting FKs
+                # across databases.
+                pieces = constraint.to.split(".")
+                if len(pieces) > 2:
+                    constraint_to = ".".join(pieces[1:])
+                else:
+                    constraint_to = constraint.to
+                return f"references {constraint_to} ({', '.join(constraint.to_columns)})"
+            else:
+                return f"references {constraint.expression}"
         else:
             return super().render_column_constraint(constraint)
 

dev-requirements.txt

@@ -1,8 +1,8 @@
 # install latest changes in dbt-core + dbt-tests-adapter
-# git+https://github.com/dbt-labs/dbt-core.git#egg=dbt-core&subdirectory=core
-# git+https://github.com/dbt-labs/dbt-adapters.git#subdirectory=dbt-tests-adapter
+git+https://github.com/dbt-labs/dbt-core.git#egg=dbt-core&subdirectory=core
+git+https://github.com/dbt-labs/dbt-adapters.git#subdirectory=dbt-tests-adapter
 
-dbt-tests-adapter==1.9.2
+#dbt-tests-adapter==1.9.2
 
 boto3
 mypy-boto3-glue