From 7aa37ea0adf864baf3ef3dfbcfaf5ff1ff780250 Mon Sep 17 00:00:00 2001
From: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Date: Mon, 9 Oct 2023 19:15:51 -0700
Subject: [PATCH] Report all stacktraces in verbose mode (#3938)

Previously these were swallowed (unlike the ones in black/__init__.py)
---
 CHANGES.md               | 2 ++
 src/black/concurrency.py | 7 +++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index fe4b621..6ad6308 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -44,6 +44,8 @@
 
 - Black no longer attempts to provide special errors for attempting to format Python 2
   code (#3933)
+- Black will more consistently print stacktraces on internal errors in verbose mode
+  (#3938)
 
 ### _Blackd_
 
diff --git a/src/black/concurrency.py b/src/black/concurrency.py
index ce01657..55c96b6 100644
--- a/src/black/concurrency.py
+++ b/src/black/concurrency.py
@@ -9,6 +9,7 @@ import logging
 import os
 import signal
 import sys
+import traceback
 from concurrent.futures import Executor, ProcessPoolExecutor, ThreadPoolExecutor
 from multiprocessing import Manager
 from pathlib import Path
@@ -170,8 +171,10 @@ async def schedule_formatting(
             src = tasks.pop(task)
             if task.cancelled():
                 cancelled.append(task)
-            elif task.exception():
-                report.failed(src, str(task.exception()))
+            elif exc := task.exception():
+                if report.verbose:
+                    traceback.print_exception(type(exc), exc, exc.__traceback__)
+                report.failed(src, str(exc))
             else:
                 changed = Changed.YES if task.result() else Changed.NO
                 # If the file was written back or was successfully checked as
-- 
2.39.2