fix(dagster-dbt): improve error messages for missing dbt adapter and invalid target_path

- Wrap `dbt.adapters` import in `compat.py` with an actionable
  ModuleNotFoundError that suggests installing the correct adapter package
- Add the same ModuleNotFoundError guard in `_initialize_dbt_core_adapter`
  for the `dbt.adapters.factory` import
- Split the bare `except:` in `cli()` adapter init into a specific
  ModuleNotFoundError branch with an installation hint, and an Exception
  fallback for other errors
- Add an explicit isinstance check for `target_path` in `cli()` to surface
  a clear ValueError instead of an AttributeError when a str is passed

Author: subramanya-dev

python_modules/libraries/dagster-dbt/dagster_dbt/compat.py

@@ -40,11 +40,19 @@
     REFABLE_NODE_TYPES: list[str] = []
 else:
     if DBT_PYTHON_VERSION is not None:
-        from dbt.adapters.base.impl import (
-            BaseAdapter as BaseAdapter,
-            BaseColumn as BaseColumn,
-            BaseRelation as BaseRelation,
-        )
+        try:
+            from dbt.adapters.base.impl import (
+                BaseAdapter as BaseAdapter,
+                BaseColumn as BaseColumn,
+                BaseRelation as BaseRelation,
+            )
+        except ModuleNotFoundError as e:
+            raise ModuleNotFoundError(
+                "A dbt adapter package could not be found.\n\n"
+                "Please install the appropriate dbt adapter for your data platform "
+                "(for example: dbt-postgres, dbt-bigquery, or dbt-snowflake).\n\n"
+                f"Original error:\n{e}"
+            ) from e
         from dbt.contracts.results import NodeStatus, TestStatus
         from dbt.node_types import NodeType as NodeType
 

python_modules/libraries/dagster-dbt/dagster_dbt/core/resource.py

@@ -361,7 +361,15 @@ def _get_unique_target_path(
         return current_target_path.joinpath(path)
 
     def _initialize_dbt_core_adapter(self, args: Sequence[str]) -> BaseAdapter:
-        from dbt.adapters.factory import get_adapter, register_adapter, reset_adapters
+        try:
+            from dbt.adapters.factory import get_adapter, register_adapter, reset_adapters
+        except ModuleNotFoundError as e:
+            raise ModuleNotFoundError(
+                "A dbt adapter package could not be found.\n\n"
+                "Please install the appropriate dbt adapter for your data platform "
+                "(for example: dbt-postgres, dbt-bigquery, or dbt-snowflake).\n\n"
+                f"Original error:\n{e}"
+            ) from e
         from dbt.config import RuntimeConfig
         from dbt.config.runtime import load_profile, load_project
         from dbt.config.utils import parse_cli_vars
@@ -646,7 +654,13 @@ def my_dbt_op(dbt: DbtCliResource):
         dagster_dbt_translator = updated_params.dagster_dbt_translator
         selection_args = updated_params.selection_args
         indirect_selection = updated_params.indirect_selection
-        target_path = target_path or self._get_unique_target_path(context=context)
+        raw_target_path = target_path or self._get_unique_target_path(context=context)
+        if not isinstance(raw_target_path, Path):
+            raise ValueError(
+                f"The 'target_path' argument must be a pathlib.Path, not {type(raw_target_path).__name__!r}."
+                " Pass a Path object, for example: target_path=Path('target')."
+            )
+        target_path = raw_target_path
         project_dir = Path(
             updated_params.dbt_project.project_dir
             if updated_params.dbt_project
@@ -717,7 +731,22 @@ def my_dbt_op(dbt: DbtCliResource):
             if self._cli_version.major < 2:
                 try:
                     adapter = self._initialize_dbt_core_adapter(args)
-                except:
+                except ModuleNotFoundError as e:
+                    if "dbt.adapters" in str(e) or "dbt-" in str(e):
+                        logger.warning(
+                            "A dbt adapter package could not be loaded. Please install the"
+                            " appropriate dbt adapter for your data platform (for example:"
+                            " dbt-postgres, dbt-bigquery, or dbt-snowflake). Some Dagster"
+                            " features that require a live connection to your data platform"
+                            " will be unavailable.\n\nOriginal error: %s",
+                            e,
+                        )
+                    else:
+                        logger.warning(
+                            "An error was encountered when creating a handle to the dbt adapter in Dagster.",
+                            exc_info=True,
+                        )
+                except Exception:
                     logger.warning(
                         "An error was encountered when creating a handle to the dbt adapter in Dagster.",
                         exc_info=True,