diff -r 5e365008360f -r 035489f60842 mercurial/commands.py
--- a/mercurial/commands.py	Fri Jul 06 10:29:09 2007 -0700
+++ b/mercurial/commands.py	Sat Jul 07 20:52:31 2007 +0200
@@ -834,7 +834,7 @@
     '''test Mercurial installation'''
 
     def writetemp(contents):
-        (fd, name) = tempfile.mkstemp()
+        (fd, name) = tempfile.mkstemp(prefix="hg-debuginstall-")
         f = os.fdopen(fd, "wb")
         f.write(contents)
         f.close()