--- a/mercurial/pvec.py	Tue Oct 08 19:35:30 2019 -0700
+++ b/mercurial/pvec.py	Sun Oct 06 20:17:41 2019 -0700
@@ -159,7 +159,7 @@
 def ctxpvec(ctx):
     '''construct a pvec for ctx while filling in the cache'''
     r = ctx.repo()
-    if not util.safehasattr(r, b"_pveccache"):
+    if not util.safehasattr(r, "_pveccache"):
         r._pveccache = {}
     pvc = r._pveccache
     if ctx.rev() not in pvc: