From 83c8aaa5b95cfe899dee322c15f2e6cd4e2837a7 Mon Sep 17 00:00:00 2001
From: tmoulignier <thibault.moulignier@cea.fr>
Date: Fri, 6 Mar 2026 16:52:18 +0100
Subject: [PATCH 1/2] Enrich displayed python error message occuring while
 serving app

---
 panel/io/handlers.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/panel/io/handlers.py b/panel/io/handlers.py
index 2978d59ea71..859f29b93f4 100644
--- a/panel/io/handlers.py
+++ b/panel/io/handlers.py
@@ -365,8 +365,10 @@ def post_check():
                 try:
                     handler._func(doc)
                 except Exception as e:
+                    error_message = ''.join(traceback.format_exception(None, e, e.__traceback__))
+                    print(error_message)
                     Alert(
-                        f'<b>{type(e).__name__}</b>\n<pre style="overflow-y: auto">{str(e)}</pre>',
+                        f'<b>{type(e).__name__}</b>\n<pre style="overflow-y: auto">{str(error_message)}</pre>',
                         alert_type='danger', margin=5, sizing_mode='stretch_width'
                     ).servable()
             elif runner is None or runner.error:

From 7cd044d961dabf9c46527f615814a442c35c5b83 Mon Sep 17 00:00:00 2001
From: Philipp Rudiger <prudiger@anaconda.com>
Date: Thu, 12 Mar 2026 13:33:46 +0100
Subject: [PATCH 2/2] Apply suggestion from @philippjfr

---
 panel/io/handlers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/panel/io/handlers.py b/panel/io/handlers.py
index 859f29b93f4..9e12c0255e9 100644
--- a/panel/io/handlers.py
+++ b/panel/io/handlers.py
@@ -366,7 +366,7 @@ def post_check():
                     handler._func(doc)
                 except Exception as e:
                     error_message = ''.join(traceback.format_exception(None, e, e.__traceback__))
-                    print(error_message)
+                    print(error_message)  # noqa
                     Alert(
                         f'<b>{type(e).__name__}</b>\n<pre style="overflow-y: auto">{str(error_message)}</pre>',
                         alert_type='danger', margin=5, sizing_mode='stretch_width'