Go back to only logging tbs on no debugger

tractor/_root.py

@@ -171,8 +171,11 @@ async def open_root_actor(
                 yield actor
 
             except (Exception, trio.MultiError) as err:
-                logger.exception("Actor crashed:")
-                await _debug._maybe_enter_pm(err)
+                # with trio.CancelScope(shield=True):
+                entered = await _debug._maybe_enter_pm(err)
+
+                if not entered:
+                    logger.exception("Root actor crashed:")
 
                 # always re-raise
                 raise