=== modified file 'a/twisted/web/test/test_webclient.py'
--- a/twisted/web/test/test_webclient.py	
+++ b/twisted/web/test/test_webclient.py	
@@ -178,6 +178,8 @@
             IOError)
 
     def testDownloadPageError3(self):
+        if not os.geteuid():
+            raise unittest.SkipTest('this does not work as root')
         # make sure failures in open() are caught too. This is tricky.
         # Might only work on posix.
         tmpfile = open("unwritable", "wb")