diff -r 7eba8f83129b -r e7aa113b14f7 mercurial/revsetlang.py
--- a/mercurial/revsetlang.py	Wed Aug 01 12:57:15 2018 -0700
+++ b/mercurial/revsetlang.py	Wed Aug 01 13:00:45 2018 -0700
@@ -63,7 +63,7 @@
 _syminitletters = set(pycompat.iterbytestr(
     string.ascii_letters.encode('ascii') +
     string.digits.encode('ascii') +
-    '._@')) | set(map(pycompat.bytechr, xrange(128, 256)))
+    '._@')) | set(map(pycompat.bytechr, pycompat.xrange(128, 256)))
 
 # default set of valid characters for non-initial letters of symbols
 _symletters = _syminitletters | set(pycompat.iterbytestr('-/'))