diff --git a/tractor/_supervise.py b/tractor/_supervise.py
index b644ef2..de26807 100644
--- a/tractor/_supervise.py
+++ b/tractor/_supervise.py
@@ -374,11 +374,12 @@ class ActorNursery:
 @acm
 async def _open_and_supervise_one_cancels_all_nursery(
     actor: Actor,
+    tb_hide: bool = False,
 
 ) -> typing.AsyncGenerator[ActorNursery, None]:
 
     # normally don't need to show user by default
-    __tracebackhide__: bool = True
+    __tracebackhide__: bool = tb_hide
 
     outer_err: BaseException|None = None
     inner_err: BaseException|None = None