Issue #26456: Force all child threads to terminate in TestForkInThread
diff --git a/Lib/test/test_thread.py b/Lib/test/test_thread.py
index b056039..b466138 100644
--- a/Lib/test/test_thread.py
+++ b/Lib/test/test_thread.py
@@ -233,7 +233,12 @@
if pid == 0: # child
os.close(self.read_fd)
os.write(self.write_fd, "OK")
- sys.exit(0)
+ # Exiting the thread normally in the child process can leave
+ # any additional threads (such as the one started by
+ # importing _tkinter) still running, and this can prevent
+ # the half-zombie child process from being cleaned up. See
+ # Issue #26456.
+ os._exit(0)
else: # parent
os.close(self.write_fd)