I have tried : Buildbot: 0.9.8 and Python 3.6.1. But the result is the same. Jacky From: Twisted-Python [mailto:twisted-python-bounces@twistedmatrix.com] On Behalf Of Craig Rodrigues Sent: Monday, June 26, 2017 12:09 PM To: Twisted general discussion Subject: Re: [Twisted-Python] Twisted ( 17.1.0 ) exception On Sunday, June 25, 2017, Jacky Chuang (莊冠世) <Jacky.Chuang@mediatek.com<mailto:Jacky.Chuang@mediatek.com>> wrote: File "d:\jacky\buildbot_virtualenv\buildbot\lib\site-packages\twisted\internet\_dumbwin32proc.py", line 214, in doCreate command, cmdline, None, None, 1, flags, env, path, StartupInfo) builtins.TypeError: Objects of type 'bytes' can not be converted to Unicode. This is a bug in buildbot. I think it was reported here: https://github.com/buildbot/buildbot/issues/3374 -- Craig