From c731209fd07116897eba3c2eedec613bfcefa47c Mon Sep 17 00:00:00 2001
From: bbhtt <bbhtt.zn0i8@slmail.me>
Date: Sat, 7 Jun 2025 18:19:41 +0530
Subject: [PATCH] Show traceback from output.json on BackendUnavailable

Fixes https://github.com/pypa/pyproject-hooks/issues/217
---
 src/pyproject_hooks/_impl.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/pyproject_hooks/_impl.py b/src/pyproject_hooks/_impl.py
index 14484fa..d82fdc2 100644
--- a/src/pyproject_hooks/_impl.py
+++ b/src/pyproject_hooks/_impl.py
@@ -53,8 +53,11 @@ def __init__(
         # Preserving arg order for the sake of API backward compatibility.
         self.backend_name = backend_name
         self.backend_path = backend_path
-        self.traceback = traceback
-        super().__init__(message or "Error while importing backend")
+        self.traceback = traceback or ""
+        super().__init__(
+            f"{message or 'Error while importing backend'}"
+            + (f"\n\nTraceback:\n{self.traceback}" if self.traceback else "")
+        )
 
 
 class HookMissing(Exception):