--- a/mercurial/dispatch.py	Wed Nov 11 00:05:12 2009 +0100
+++ b/mercurial/dispatch.py	Wed Nov 04 13:44:15 2009 -0600
@@ -279,7 +279,8 @@
                 raise IndexError
             ui.setconfig(section, name, value)
         except (IndexError, ValueError):
-            raise util.Abort(_('malformed --config option: %s') % cfg)
+            raise util.Abort(_('malformed --config option: %r '
+                               '(use --config section.name=value)') % cfg)
 
 def _earlygetopt(aliases, args):
     """Return list of values for an option (or aliases).