diff -r 414a3513c2bd -r a8994d08e4a2 mercurial/dagparser.py
--- a/mercurial/dagparser.py	Sun Sep 03 15:47:17 2017 +0900
+++ b/mercurial/dagparser.py	Sun Sep 03 14:56:31 2017 +0900
@@ -155,8 +155,9 @@
 
     Error:
 
+        >>> from . import pycompat
         >>> try: list(parsedag(b'+1 bad'))
-        ... except Exception, e: print(e)
+        ... except Exception, e: print(pycompat.sysstr(bytes(e)))
         invalid character in dag description: bad...
 
     '''