This is a problem in twisted. Buldbot uses twisted. To make buildbot git polling work for me, I had to make the change below. Based on zturner comment #17 in http://trac.buildbot.net/ticket/2936 Win 10 Pro, Version 1703, OS Build 15063.138, 64 bit Python 2.7 Buildbot version: 0.9.5 Twisted version: 17.1.0 $ diff -uprN _dumbwin32proc.py.orig _dumbwin32proc.py --- _dumbwin32proc.py.orig 2017-04-18 08:25:31.639822200 -0700 +++ _dumbwin32proc.py 2017-04-18 08:25:43.310989300 -0700 @@ -210,7 +210,7 @@ class Process(_pollingfile._PollingTimer # TODO: error detection here. See #2787 and #4184. def doCreate(): self.hProcess, self.hThread, self.pid, dwTid = win32process.CreateProcess( - command, cmdline, None, None, 1, 0, env, path, StartupInfo) + None, cmdline, None, None, 1, 0, env, path, StartupInfo) try: try: doCreate()