intermittent test_signalKILL failure on BSD

New submission from exarkun <[email protected]>:

This failure shows up not infrequently on at least the FreeBSD builders:

{{{
===============================================================================
[ERROR]: twisted.test.test_process.PosixProcessTestCase.test_signalKILL

Traceback (most recent call last):
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/selectreactor.py", line 146, in _doReadOrWrite
    why = getattr(selectable, method)()
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/process.py", line 240, in doRead
    return fdesc.readFromFD(self.fd, self.dataReceived)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/fdesc.py", line 94, in readFromFD
    callback(output)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/process.py", line 243, in dataReceived
    self.proc.childDataReceived(self.name, data)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/process.py", line 745, in childDataReceived
    self.proto.childDataReceived(name, data)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/protocol.py", line 451, in childDataReceived
    self.outReceived(data)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/test/test_process.py", line 274, in outReceived
    self.transport.signalProcess(self.signal)
  File "/usr/home/wiqd/twisted/freebsd-py2.6-select/Twisted/twisted/internet/process.py", line 322, in signalProcess
    raise ProcessExitedAlready()
twisted.internet.error.ProcessExitedAlready: 
-------------------------------------------------------------------------------
}}}


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Type     : defect
Component: core
Keywords : 
Priority : normal
Nosy     : 
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http://twistedmatrix.com/trac/ticket/4186