--- a/mercurial/subrepo.py	Thu Mar 29 09:34:17 2018 -0700
+++ b/mercurial/subrepo.py	Thu Mar 29 09:23:39 2018 -0700
@@ -724,7 +724,7 @@
         ssh = opts.get('ssh')
 
         # push subrepos depth-first for coherent ordering
-        c = self._repo['']
+        c = self._repo['.']
         subs = c.substate # only repos that are committed
         for s in sorted(subs):
             if c.sub(s).push(opts) == 0: