From 81f5f5b8d4d3e4c86be2fa626c2321ef6024aad2 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Wed, 7 May 2025 12:34:13 +0900
Subject: [PATCH] mruby-bin-debugger: should not use Exception#inspect to print
 errors

Use mrb_exc_get_output() instead.
---
 mrbgems/mruby-bin-debugger/tools/mrdb/apiprint.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/mrbgems/mruby-bin-debugger/tools/mrdb/apiprint.c b/mrbgems/mruby-bin-debugger/tools/mrdb/apiprint.c
index 49c93e21c..a383f3aab 100644
--- a/mrbgems/mruby-bin-debugger/tools/mrdb/apiprint.c
+++ b/mrbgems/mruby-bin-debugger/tools/mrdb/apiprint.c
@@ -11,6 +11,7 @@
 #include <mruby/error.h>
 #include <mruby/numeric.h>
 #include <mruby/string.h>
+#include <mruby/internal.h>
 #include <mruby/presym.h>
 #include "apiprint.h"
 
@@ -70,12 +71,15 @@ mrb_debug_eval(mrb_state *mrb, mrb_debug_context *dbg, const char *expr, size_t
 
     v =  mrb_funcall_argv(mrb, recv, MRB_SYM(instance_eval), 1, &ruby_code);
   }
-
-  if (exc) {
-    *exc = mrb_obj_is_kind_of(mrb, v, E_EXCEPTION);
+  mrb_bool is_exc = mrb_obj_is_kind_of(mrb, v, E_EXCEPTION);
+  if (is_exc) {
+    s = mrb_exc_get_output(mrb, mrb_obj_ptr(v));
+  }
+  else {
+    s = mrb_inspect(mrb, v);
   }
 
-  s = mrb_inspect(mrb, v);
+  if (exc) *exc = is_exc;
 
   /* enable code_fetch_hook */
   mrb->code_fetch_hook = tmp;