[Buildbot-devel] HgPoller exception "while polling for changes"

[Steve Hoelzer]

I'm running Buildbot 0.8.8 on Windows 7 and Python 2.7.6. I have it
working well enough that clicking "force build" will update from a
Mercurial repository and send a status email. Now I'm trying to get
HgPoller working. Here is how I create it:

    from buildbot.changes.hgpoller import HgPoller
    c['change_source'].append(
        HgPoller(
            repourl='http://path/to/repo',
            branch='default',
            workdir='hgpoller-workdir',
            pollinterval=15*60,
            project='test'))

It does run periodically, but always fails. It doesn't even get far
enough to create 'hgpoller-workdir' on disk. Here's the error from
twistd.log:

    2013-11-15 10:50:07-0600 [-] hgpoller: initializing working dir
from http://path/to/repo/
    2013-11-15 10:50:07-0600 [-] while polling for changes
    Traceback (most recent call last):
     File "C:\Python27\lib\site-packages\twisted\internet\defer.py",
line 306, in addCallback
       callbackKeywords=kw)
     File "C:\Python27\lib\site-packages\twisted\internet\defer.py",
line 295, in addCallbacks
       self._runCallbacks()
     File "C:\Python27\lib\site-packages\twisted\internet\defer.py",
line 577, in _runCallbacks
       current.result = callback(current.result, *args, **kw)
     File "C:\Python27\lib\site-packages\twisted\internet\defer.py",
line 1276, in execute
       d = maybeDeferred(f, *args, **kwargs)
    --- <exception caught here> ---
     File "C:\Python27\lib\site-packages\twisted\internet\defer.py",
line 139, in maybeDeferred
       result = f(*args, **kw)
     File "C:\Python27\lib\site-packages\buildbot-0.8.8-py2.7.egg\buildbot\changes\hgpoller.py",
line 74, in poll
       d = self._getChanges()
     File "C:\Python27\lib\site-packages\buildbot-0.8.8-py2.7.egg\buildbot\changes\hgpoller.py",
line 141, in _getChanges
       d = self._initRepository()
     File "C:\Python27\lib\site-packages\buildbot-0.8.8-py2.7.egg\buildbot\changes\hgpoller.py",
line 131, in _initRepository
       env=os.environ)
     File "C:\Python27\lib\site-packages\twisted\internet\utils.py",
line 176, in getProcessOutputAndValue
       reactor)
     File "C:\Python27\lib\site-packages\twisted\internet\utils.py",
line 30, in _callProtocolWithDeferred
       reactor.spawnProcess(p, executable, (executable,)+tuple(args), env, path)
     File "C:\Python27\lib\site-packages\twisted\internet\posixbase.py",
line 358, in spawnProcess
       return Process(self, processProtocol, executable, args, env, path)
     File "C:\Python27\lib\site-packages\twisted\internet\_dumbwin32proc.py",
line 195, in __init__
       raise OSError(pwte)
    exceptions.OSError: (2, 'CreateProcess', 'The system cannot find
the file specified.')

This seems to point to Twisted. I have version 13.2.0 installed from
the msi here: http://twistedmatrix.com/trac/wiki/Downloads

[As a side note, I tried 'easy_install buildbot' which wanted to get
Twisted but that failed saying 'unable to find vcvarsall.bat'.]

I'm not sure how to debug this further. Is it a problem with my
install, or with Twisted, or with HgPoller? What should I do next?

Thanks,
Steve