Issue #18441: fix buildbot name-error for TclError.
diff --git a/Lib/test/test_idle.py b/Lib/test/test_idle.py
index 540f7d2..79d18a8 100644
--- a/Lib/test/test_idle.py
+++ b/Lib/test/test_idle.py
@@ -10,7 +10,7 @@
     try:
         root = tk.Tk()
         root.destroy()
-    except TclError:
+    except tk.TclError:
         while True:
             use_resources.delete('gui')
             if 'gui' not in use_resources: