Oops.  A RISCOS patch I forgot to check in.
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index d77120e..34b1809 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -55,7 +55,13 @@
         return cmp(len(x), len(y))
     return cmp(x, y)
 
-TESTFN = '@test' # Filename used for testing
+import os
+if os.name !='riscos':
+    TESTFN = '@test' # Filename used for testing
+else:
+    TESTFN = 'test' # Filename used for testing
+del os
+
 from os import unlink
 
 def findfile(file, here=__file__):