diff -r 08cc94dd3d3c -r ba15580e53d5 mercurial/wireproto.py
--- a/mercurial/wireproto.py	Sat Jan 20 15:26:31 2018 -0800
+++ b/mercurial/wireproto.py	Sat Jan 20 13:41:57 2018 -0800
@@ -877,8 +877,8 @@
                     _('server has pull-based clones disabled'),
                     hint=_('remove --pull if specified or upgrade Mercurial'))
 
-        chunks = exchange.getbundlechunks(repo, 'serve',
-                                          **pycompat.strkwargs(opts))
+        info, chunks = exchange.getbundlechunks(repo, 'serve',
+                                                **pycompat.strkwargs(opts))
     except error.Abort as exc:
         # cleanly forward Abort error to the client
         if not exchange.bundle2requested(opts.get('bundlecaps')):