core(launcher): Force exit on early exception:

The backend was not properly exiting in case of early exception (e.g. configuration
error). It seems to be related to the use of the `@aio` decorator, but couldn't find the
exact issue with loop. The use of `os._exit` is a workaround for now, until the fix is
inspected more deeply and properly fixed.

libervia/backend/core/launcher.py

@@ -312,10 +312,16 @@ class Launcher:
             runner.run()
             if runner._exitSignal is not None:
                 app._exitWithSignal(runner._exitSignal)
+            # FIXME: The loop is not closing correctly as soon as
+            #   libervia.backend.tools.utils.aio decoractor is used. Asyncio loop doesn't
+            #   seem to have any task left, and reactor is stopped, but there is still
+            #   something preventing proper exit. `os._exit` is not great, but currently
+            #   the way to actually close the backend in this case. This needs further
+            #   investigation.
             try:
-                sys.exit(app._exit_code)
+                os._exit(app._exit_code)
             except AttributeError:
-                pass
+                os._exit(C.EXIT_ERROR)
 
     @classmethod
     def run(cls):

libervia/backend/core/main.py

@@ -284,9 +284,11 @@ class LiberviaBackend(service.Service):
                 f"Configuration error, please check and fix your configuration: {e}"
             )
             self.stop(exit_code=C.EXIT_BAD_ARG)
+            return
         except Exception:
             log.exception(f"Could not initialize backend")
             self.stop(exit_code=C.EXIT_ERROR)
+            return
         self._add_base_menus()
 
         self.init_pre_script.callback(None)