diff -r edf07a804ac4 -r 1f72226064b8 mercurial/formatter.py
--- a/mercurial/formatter.py	Fri Sep 12 18:32:46 2014 -0500
+++ b/mercurial/formatter.py	Fri Sep 12 19:06:11 2014 -0500
@@ -67,12 +67,12 @@
 class debugformatter(baseformatter):
     def __init__(self, ui, topic, opts):
         baseformatter.__init__(self, ui, topic, opts)
-        self._ui.write("%s = {\n" % self._topic)
+        self._ui.write("%s = [\n" % self._topic)
     def _showitem(self):
         self._ui.write("    " + repr(self._item) + ",\n")
     def end(self):
         baseformatter.end(self)
-        self._ui.write("}\n")
+        self._ui.write("]\n")
 
 def formatter(ui, topic, opts):
     if ui.configbool('ui', 'formatdebug'):