--- a/mercurial/smartset.py	Sat Jan 27 17:31:25 2018 +0900
+++ b/mercurial/smartset.py	Sat Jan 27 17:46:37 2018 +0900
@@ -29,7 +29,7 @@
     if r is None:
         return ''
     elif isinstance(r, tuple):
-        return r[0] % r[1:]
+        return r[0] % util.rapply(pycompat.maybebytestr, r[1:])
     elif isinstance(r, bytes):
         return r
     elif callable(r):