--- a/hgext3rd/pullbundle.py	Thu Dec 19 18:16:18 2019 +0700
+++ b/hgext3rd/pullbundle.py	Fri Dec 20 13:50:31 2019 +0700
@@ -611,19 +611,20 @@
         b'max': data[-1],
     }
 
-STATSFORMAT = b"""{name}:
-  min: {min}
-  10%: {10%}
-  25%: {25%}
-  50%: {50%}
-  75%: {75%}
-  90%: {90%}
-  95%: {95%}
-  max: {max}
+STATSFORMAT = b"""%(name)s:
+  min: %(min)r
+  10%%: %(10%)r
+  25%%: %(25%)r
+  50%%: %(50%)r
+  75%%: %(75%)r
+  90%%: %(90%)r
+  95%%: %(95%)r
+  max: %(max)r
 """
 
 def fmtdist(name, data):
-    return STATSFORMAT.format(name=name, **data)
+    data[b'name'] = name
+    return STATSFORMAT % data
 
 # hg <= 4.6 (bec1212eceaa)
 if util.safehasattr(uimod.ui, 'makeprogress'):