From 2b00a0cea141fab54dd15e52bba34fea2ab832ac Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Tue, 15 Apr 2025 10:10:02 -0400
Subject: [PATCH] feat(exn_bt): in show/pp, do print the backtrace when present

---
 src/core/exn_bt.ml | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/core/exn_bt.ml b/src/core/exn_bt.ml
index cfed6421..4931b96f 100644
--- a/src/core/exn_bt.ml
+++ b/src/core/exn_bt.ml
@@ -3,7 +3,15 @@ type t = exn * Printexc.raw_backtrace
 let[@inline] make exn bt : t = exn, bt
 let[@inline] exn (e, _) = e
 let[@inline] bt (_, bt) = bt
-let show self = Printexc.to_string (exn self)
+
+let show self =
+  let bt = Printexc.raw_backtrace_to_string (bt self) in
+  let exn = Printexc.to_string (exn self) in
+  if bt = "" then
+    exn
+  else
+    Printf.sprintf "%s\n%s" exn bt
+
 let pp out self = Format.pp_print_string out (show self)
 let[@inline] raise (e, bt) = Printexc.raise_with_backtrace e bt