[Python-buildbots] Internal buildbot error?

[David Bolen]

It does seem like it might be a race condition of some sort - or at least
an unhandled case - in Twisted's process handling.

It's in the writer path, so I wonder if the umask operation completes
quickly enough, perhaps the output handle is in fact invalid by the time
the buildbot parent gets to that section of code.  The umask step looks
like it's only used by the DMG builder, not for regular test builds.

It's fairly uncommon - just twice so far across all branches under the new
master.  To be honest, we could probably just eliminate that step at this
point from the DMG builds (not sure it serves much purpose) or maybe add a
small sleep along with the umask to ensure the child process is around long
enough for the parent to complete the setup.

 -- David

On Thu, Dec 21, 2017 at 5:27 PM, Victor Stinner <victor.stinner at gmail.com>
wrote:

> Hi,
>
> What is the following failure? Can it be an internal buildbot bot?
>
> http://buildbot.python.org/all/#/builders/69/builds/75
>
> error in RunProcess._startCommand
> Traceback (most recent call last):
> File "/Library/Frameworks/Python.framework/Versions/2.7/lib/
> python2.7/site-packages/buildslave/runprocess.py",
> line 426, in start
> self._startCommand()
> File "/Library/Frameworks/Python.framework/Versions/2.7/lib/
> python2.7/site-packages/buildslave/runprocess.py",
> line 550, in _startCommand
> usePTY=self.usePTY)
> File "/Library/Frameworks/Python.framework/Versions/2.7/lib/
> python2.7/site-packages/buildslave/runprocess.py",
> line 572, in _spawnProcess
> processProtocol, uid, gid, childFDs)
> File "/Library/Frameworks/Python.framework/Versions/2.7/lib/
> python2.7/site-packages/twisted/internet/process.py",
> line 747, in __init__
> parentFD, forceReadHack=True)
> File "/Library/Frameworks/Python.framework/Versions/2.7/lib/
> python2.7/site-packages/twisted/internet/process.py",
> line 156, in __init__
> if not stat.S_ISFIFO(os.fstat(self.fileno()).st_mode):
> OSError: [Errno 9] Bad file descriptor
>
> Traceback (most recent call last):
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> twisted/internet/defer.py",
> line 500, in errback
>     self._startRunCallbacks(fail)
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> twisted/internet/defer.py",
> line 567, in _startRunCallbacks
>     self._runCallbacks()
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> twisted/internet/defer.py",
> line 653, in _runCallbacks
>     current.result = callback(current.result, *args, **kw)
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> twisted/internet/defer.py",
> line 1442, in gotResult
>     _inlineCallbacks(r, g, deferred)
> --- <exception caught here> ---
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> twisted/internet/defer.py",
> line 1386, in _inlineCallbacks
>     result = g.send(result)
>   File "/data/buildbot/venv/lib/python3.4/site-packages/
> buildbot/process/buildstep.py",
> line 705, in run
>     results = yield self._start_deferred
> builtins.TypeError: Can't convert 'bytes' object to str implicitly
>
> Victor
> _______________________________________________
> Python-Buildbots mailing list
> Python-Buildbots at python.org
> https://mail.python.org/mailman/listinfo/python-buildbots
>