diff -r bcc1a9fd0b8c -r a95efd378641 hgext/extdiff.py
--- a/hgext/extdiff.py	Fri Jun 24 17:04:37 2011 +0300
+++ b/hgext/extdiff.py	Fri Jun 24 17:04:37 2011 +0300
@@ -222,7 +222,7 @@
         cmdline = util.shellquote(diffcmd) + ' ' + args
 
         ui.debug('running %r in %s\n' % (cmdline, tmproot))
-        util.system(cmdline, cwd=tmproot)
+        util.system(cmdline, cwd=tmproot, out=ui.fout)
 
         for copy_fn, working_fn, mtime in fns_and_mtime:
             if os.lstat(copy_fn).st_mtime != mtime: