[Buildbot] #3546: MasterShellCommand ends up in exception

[Buildbot trac]

#3546: MasterShellCommand ends up in exception
---------------------+-----------------------
Reporter:  gracinet  |      Owner:
    Type:  defect    |     Status:  new
Priority:  major     |  Milestone:  undecided
 Version:  master    |   Keywords:
---------------------+-----------------------
 I've got a `MasterShellCommand` whose execution is ok (exit code is 0),
 yet whose result is EXCEPTION

 There's no info on the Web UI, but here's what landed in `twistd.log`

 {{{
 2016-05-07 13:27:15+0200 [-] from an asynchronous method executed in an
 old-style step
         Traceback (most recent call last):
           File "/srv/buildbot9/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 1184, in gotResult
             _inlineCallbacks(r, g, deferred)
           File "/srv/buildbot9/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 1131, in _inlineCallbacks
             deferred.callback(getattr(e, "value", None))
           File "/srv/buildbot9/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 393, in callback
             self._startRunCallbacks(result)
           File "/srv/buildbot9/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 501, in _startRunCallbacks
             self._runCallbacks()
         --- <exception caught here> ---
           File "/srv/buildbot9/local/lib/python2.7/site-
 packages/twisted/internet/defer.py", line 588, in _runCallbacks
             current.result = callback(current.result, *args, **kw)
           File "/srv/buildbot9/buildbot-
 git/master/buildbot/process/buildstep.py", line 169, in next
             self._catchup()
           File "/srv/buildbot9/buildbot-
 git/master/buildbot/process/buildstep.py", line 171, in _catchup
             self.step._start_unhandled_deferreds.append(d)
         exceptions.AttributeError: 'NoneType' object has no attribute
 'append'

 2016-05-07 13:27:15+0200 [-] Unhandled error in Deferred:
 }}}

 (and then the same error gets repeated several times).
 I've already checked that the 'old-style step' message is directly related
 to the Exception status

 Precise rev (git describe): v0.9.0b8-229-g96f42bb

--
Ticket URL: <http://trac.buildbot.net/ticket/3546>
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Buildbot: build/test automation