From e9785ca87c434f59743b46cd23ad9e2ef6bca983 Mon Sep 17 00:00:00 2001
From: Tim Rid <6593626+timrid@users.noreply.github.com>
Date: Tue, 12 Aug 2025 21:47:49 +0200
Subject: [PATCH] use threading.__file__ als last fallback

---
 src/debugpy/_vendored/pydevd/pydevd_file_utils.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/debugpy/_vendored/pydevd/pydevd_file_utils.py b/src/debugpy/_vendored/pydevd/pydevd_file_utils.py
index ab13b2bc..7ca38344 100644
--- a/src/debugpy/_vendored/pydevd/pydevd_file_utils.py
+++ b/src/debugpy/_vendored/pydevd/pydevd_file_utils.py
@@ -89,10 +89,13 @@ def _get_library_dir():
 
     if library_dir is None or not os_path_exists(library_dir):
         if hasattr(os, "__file__"):
+            # "os" is a frozen import an thus "os.__file__" is not always set.
+            # See https://github.com/python/cpython/pull/28656
             library_dir = os.path.dirname(os.__file__)
-
-    if library_dir is None:
-        library_dir = ""  # not possible to detect library_dir
+        else:
+            # "threading" is not a frozen import an thus "threading.__file__" is always set.
+            import threading
+            library_dir = os.path.dirname(threading.__file__)
 
     return library_dir