diff -r bbcbb82e3589 -r 66f2cc210a29 mercurial/__init__.py
--- a/mercurial/__init__.py	Sun Oct 06 14:51:45 2019 -0400
+++ b/mercurial/__init__.py	Sun Oct 06 14:58:42 2019 -0400
@@ -171,7 +171,7 @@
                 r, c = t.start
                 l = (
                     b'; from mercurial.pycompat import '
-                    b'delattr, getattr, hasattr, setattr\n'
+                    b'delattr, getattr, hasattr\n'
                 )
                 for u in tokenize.tokenize(io.BytesIO(l).readline):
                     if u.type in (tokenize.ENCODING, token.ENDMARKER):
@@ -220,7 +220,7 @@
     # ``replacetoken`` or any mechanism that changes semantics of module
     # loading is changed. Otherwise cached bytecode may get loaded without
     # the new transformation mechanisms applied.
-    BYTECODEHEADER = b'HG\x00\x0e'
+    BYTECODEHEADER = b'HG\x00\x0f'
 
     class hgloader(importlib.machinery.SourceFileLoader):
         """Custom module loader that transforms source code.