Issue #13841: Make child processes exit using sys.exit() on Windows
diff --git a/Lib/test/support.py b/Lib/test/support.py
index 6749a51..3ff1df5 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -1593,7 +1593,7 @@
     This will typically be run on the result of the communicate() method
     of a subprocess.Popen object.
     """
-    stderr = re.sub(br"\[\d+ refs\]\r?\n?$", b"", stderr).strip()
+    stderr = re.sub(br"\[\d+ refs\]\r?\n?", b"", stderr).strip()
     return stderr
 
 def args_from_interpreter_flags():