fix(ingest/dagster): Fix Dagster build (#12121)

.github/workflows/dagster-plugin.yml

@@ -31,9 +31,9 @@ jobs:
       DATAHUB_TELEMETRY_ENABLED: false
     strategy:
       matrix:
-        python-version: ["3.8", "3.10"]
+        python-version: ["3.9", "3.10"]
         include:
-          - python-version: "3.8"
+          - python-version: "3.9"
             extraPythonRequirement: "dagster>=1.3.3"
           - python-version: "3.10"
             extraPythonRequirement: "dagster>=1.3.3"

metadata-ingestion-modules/dagster-plugin/setup.py

@@ -123,7 +123,7 @@ def get_long_description():
     ],
     # Package info.
     zip_safe=False,
-    python_requires=">=3.8",
+    python_requires=">=3.9",
     package_dir={"": "src"},
     packages=setuptools.find_namespace_packages(where="./src"),
     entry_points=entry_points,

metadata-ingestion-modules/dagster-plugin/src/datahub_dagster_plugin/sensors/datahub_sensors.py

@@ -28,10 +28,15 @@
 from dagster._core.definitions.multi_asset_sensor_definition import (
     AssetMaterializationFunctionReturn,
 )
-from dagster._core.definitions.sensor_definition import (
-    DefaultSensorStatus,
-    RawSensorEvaluationFunctionReturn,
-)
+from dagster._core.definitions.sensor_definition import DefaultSensorStatus
+
+# This SensorReturnTypesUnion is from Dagster 1.9.1+ and is not available in older versions
+# of Dagster. We need to import it conditionally to avoid breaking compatibility with older
+try:
+    from dagster._core.definitions.sensor_definition import SensorReturnTypesUnion
+except ImportError:
+    from dagster._core.definitions.sensor_definition import RawSensorEvaluationFunctionReturn as SensorReturnTypesUnion  # type: ignore
+
 from dagster._core.definitions.target import ExecutableDefinition
 from dagster._core.definitions.unresolved_asset_job_definition import (
     UnresolvedAssetJobDefinition,
@@ -689,9 +694,7 @@ def _emit_asset_metadata(
 
         return SkipReason("Asset metadata processed")
 
-    def _emit_metadata(
-        self, context: RunStatusSensorContext
-    ) -> RawSensorEvaluationFunctionReturn:
+    def _emit_metadata(self, context: RunStatusSensorContext) -> SensorReturnTypesUnion:
         """
         Function to emit metadata for datahub rest.
         """