add missing `StackNotFoundError` import
@@ -25,7 +25,7 @@ import grpc
from ._cmd import CommandResult, _run_pulumi_cmd, OnOutput
from ._config import ConfigValue, ConfigMap
-from .errors import StackAlreadyExistsError
+from .errors import StackAlreadyExistsError, StackNotFoundError
from .events import OpMap, EngineEvent, SummaryEvent
from ._output import OutputMap
from ._server import LanguageServer
