diff -r 93aeebc90ff9 -r be384a2052aa contrib/perf.py
--- a/contrib/perf.py	Tue Nov 05 12:10:38 2019 -0500
+++ b/contrib/perf.py	Tue Nov 05 08:42:42 2019 -0800
@@ -691,8 +691,8 @@
         def clearcache():
             # _tagscache has been filteredpropertycache since 2.5 (or
             # 98c867ac1330), and delattr() can't work in such case
-            if b'_tagscache' in vars(repo):
-                del repo.__dict__[b'_tagscache']
+            if '_tagscache' in vars(repo):
+                del repo.__dict__['_tagscache']
 
         return clearcache