From c42de1e4939de459269a1c08e621731677174ee0 Mon Sep 17 00:00:00 2001
From: Thomas Leonard <talex5@gmail.com>
Date: Tue, 2 Jan 2024 16:26:40 +0000
Subject: [PATCH] Remove default backtrace from Switch.fail

If you didn't pass a backtrace then it would attach a bogus one,
which was confusing.
---
 lib_eio/core/switch.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib_eio/core/switch.ml b/lib_eio/core/switch.ml
index 245e6ba40..25f770e3a 100644
--- a/lib_eio/core/switch.ml
+++ b/lib_eio/core/switch.ml
@@ -47,7 +47,7 @@ let combine_exn ex = function
   | Some ex1 -> Exn.combine ex1 ex
 
 (* Note: raises if [t] is finished or called from wrong domain. *)
-let fail ?(bt=Printexc.get_raw_backtrace ()) t ex =
+let fail ?(bt=Printexc.get_callstack 0) t ex =
   check_our_domain t;
   if t.exs = None then
     Trace.error t.cancel.id ex;