--- a/hgext3rd/evolve/stablesort.py	Thu Jul 11 14:31:32 2019 -0700
+++ b/hgext3rd/evolve/stablesort.py	Tue Jul 09 10:56:42 2019 -0700
@@ -620,9 +620,9 @@
             indexsizedata = data[offset:offset + S_INDEXSIZE.size]
             indexsize = S_INDEXSIZE.unpack(indexsizedata)[0]
             offset += S_INDEXSIZE.size
-            self._index.fromstring(data[offset:offset + indexsize])
+            compat.arrayfrombytes(self._index, data[offset:offset + indexsize])
             offset += indexsize
-            self._data.fromstring(data[offset:])
+            compat.arrayfrombytes(self._data, data[offset:])
         self._ondiskkey = self._cachekey
         pass
 
@@ -638,8 +638,8 @@
 
             # data to write
             headerdata = self._serializecachekey()
-            indexdata = self._index.tostring()
-            data = self._data.tostring()
+            indexdata = compat.arraytobytes(self._index)
+            data = compat.arraytobytes(self._data)
             indexsize = S_INDEXSIZE.pack(len(indexdata))
 
             # writing