There is an issue https://bugs.python.org/issue1652
in Python 2.7 which was resolved in Py3.
By default Python sets SIGPIPE to SIG_IGN on startup, because
it prefers to check every write and raise an IOError exception rather
than taking SIGPIPE. This is all well and good for Python itself.
However, non-Python Unix subprocesses generally expect to have
SIGPIPE set to the default action, since that's what will happen if
they're started from a normal shell.
As a result scripts with piping that is terminated in reverse chain
order are never exit.
See more info here:
http://www.enricozini.org/blog/2009/debian/python-pipes/
Closes-Bug: #1524347
Change-Id: Ia015e7fd46912f6a0be97a6b9c297f8d14fd3f7c
75e7e04695