diff -r f694e20193f2 -r 98e8313dcd9e mercurial/revset.py
--- a/mercurial/revset.py	Tue Jun 07 12:10:01 2016 +0200
+++ b/mercurial/revset.py	Tue Jun 14 11:53:55 2016 +0200
@@ -2663,7 +2663,8 @@
                 ret += listexp(list(args[arg]), d)
                 arg += 1
             else:
-                raise error.Abort('unexpected revspec format character %s' % d)
+                raise error.Abort(_('unexpected revspec format character %s')
+                                  % d)
         else:
             ret += c
         pos += 1