gh-161166: Fix incorrect exception line in asyncio.Task.print_stack()

Author: deadlovelll

Lib/asyncio/base_tasks.py

@@ -67,10 +67,18 @@ def _task_get_stack(task, limit):
 
 
 def _task_print_stack(task, limit, file):
+    # gh-161166: use the traceback line number instead of the frame’s current line number
+    # because it can give false exception causes
+    exc = task._exception
+    tb = exc.__traceback__ if exc is not None else None
     extracted_list = []
     checked = set()
     for f in task.get_stack(limit=limit):
-        lineno = f.f_lineno
+        if tb is not None:
+            lineno = tb.tb_lineno
+            tb = tb.tb_next
+        else:
+            lineno = f.f_lineno
         co = f.f_code
         filename = co.co_filename
         name = co.co_name
@@ -80,7 +88,6 @@ def _task_print_stack(task, limit, file):
         line = linecache.getline(filename, lineno, f.f_globals)
         extracted_list.append((filename, lineno, name, line))
 
-    exc = task._exception
     if not extracted_list:
         print(f'No stack for {task!r}', file=file)
     elif exc is not None:

Lib/test/test_asyncio/test_tasks.py

@@ -335,6 +335,21 @@ async def runner():
 
         self.loop.run_until_complete(runner())
 
+    def test_print_stack_exception_lineno(self):
+        # gh-161166
+        async def coro():
+            try:
+                1 / 0
+            finally:
+                cleaned = True
+
+        task = self.new_task(self.loop, coro())
+        test_utils.run_briefly(self.loop)
+        task.exception()
+        file = io.StringIO()
+        task.print_stack(file=file)
+        self.assertIn('    1 / 0\n', file.getvalue())
+
     def test_task_repr(self):
         self.loop.set_debug(False)
 

Misc/NEWS.d/next/Library/2026-11-02-13-11-30.gh-issue-161166.zfFDlW.rst

@@ -0,0 +1,2 @@
+Fix :meth:asyncio.Task.print_stack displaying an incorrect exception line
+after a finally block. Patch by Timofei Ivankov.