--- a/mercurial/commands.py	Thu Mar 29 09:34:17 2018 -0700
+++ b/mercurial/commands.py	Thu Mar 29 09:23:39 2018 -0700
@@ -4166,7 +4166,7 @@
     repo._subtoppath = dest
     try:
         # push subrepos depth-first for coherent ordering
-        c = repo['']
+        c = repo['.']
         subs = c.substate # only repos that are committed
         for s in sorted(subs):
             result = c.sub(s).push(opts)