Set the default work start method to spawn on MacOS

src/lightning_app/components/serve/gradio.py

@@ -34,8 +34,6 @@ class ServeGradio(LightningWork, abc.ABC):
     title: Optional[str] = None
     description: Optional[str] = None
 
-    _start_method = "spawn"
-
     def __init__(self, *args, **kwargs):
         requires("gradio")(super().__init__(*args, **kwargs))
         assert self.inputs

src/lightning_app/components/serve/python_server.py

@@ -64,9 +64,6 @@ def _get_sample_data() -> Dict[Any, Any]:
 
 
 class PythonServer(LightningWork, abc.ABC):
-
-    _start_method = "spawn"
-
     @requires(["torch"])
     def __init__(  # type: ignore
         self,

src/lightning_app/core/work.py

@@ -55,8 +55,7 @@ class LightningWork:
     )
 
     _run_executor_cls: Type[WorkRunExecutor] = WorkRunExecutor
-    # TODO: Move to spawn for all Operating System.
-    _start_method = "spawn" if sys.platform == "win32" else "fork"
+    _start_method = "spawn"
 
     def __init__(
         self,