diff -r 8122cc5cb543 -r 492c64afc54c mercurial/dispatch.py
--- a/mercurial/dispatch.py	Sat Feb 25 17:29:30 2017 +0900
+++ b/mercurial/dispatch.py	Fri Mar 17 05:10:58 2017 +0530
@@ -286,7 +286,7 @@
             if num < len(givenargs):
                 return givenargs[num]
             raise error.Abort(_('too few arguments for command alias'))
-        cmd = re.sub(r'\$(\d+|\$)', replacer, cmd)
+        cmd = re.sub(br'\$(\d+|\$)', replacer, cmd)
         givenargs = [x for i, x in enumerate(givenargs)
                      if i not in nums]
         args = pycompat.shlexsplit(cmd)