Issue #18174: Fix fd leaks in tests.
diff --git a/Lib/test/test_uuid.py b/Lib/test/test_uuid.py
index 6fe2fe5..9de3d78 100644
--- a/Lib/test/test_uuid.py
+++ b/Lib/test/test_uuid.py
@@ -448,6 +448,7 @@
 
         else:
             os.close(fds[1])
+            self.addCleanup(os.close, fds[0])
             parent_value = uuid.uuid4().hex
             os.waitpid(pid, 0)
             child_value = os.read(fds[0], 100)