--- a/mercurial/pycompat.py	Sun Oct 06 09:45:02 2019 -0400
+++ b/mercurial/pycompat.py	Sun Oct 06 09:48:39 2019 -0400
@@ -356,7 +356,7 @@
     bytesurl = identity
 
     # this can't be parsed on Python 3
-    exec('def raisewithtb(exc, tb):\n' '    raise exc, None, tb\n')
+    exec(b'def raisewithtb(exc, tb):\n' b'    raise exc, None, tb\n')
 
     def fsencode(filename):
         """